Music played a significant role in missionary efforts in the Southwestern States Mission. In this post I briefly list some of the ways missionaries used music.
[Also: I have divided the footnotes: letters indicate comment or explanation, numbers have only examples.]
The standard proselyting vehicle for the missionaries was the “meeting.” After arranging for a space—school, church, living room, etc—they would go door-to-door announcing the time and place. When the people had gathered they would “[open] as usual by singing and Prayer.” [a] A common sequence was:
song – prayer – song – introduction – speaker – speaker – song – prayer. [b]
Sometimes “the people did the singing” and sometimes the missionaries did; the diaries aren’t clear enough to be confident, but my vague impression is that missionaries sang in front more often than they sang with. [c] In some cases the missionaries used singing to fill time while waiting for more people to arrive. 
“Street meetings” were a tool for urban rather than rural proselyting. The pattern seems to have been to sing two hymns to draw attention and then open the meeting; they also sometimes closed with a hymn.  When Emma Ramsey, a prominent Utah soprano, visited the mission in 1905 she participated in a street meeting and, according to Sister Cluff, “her beautiful voice attracted much notice.” [d] President Duffin “took several of the Elders out to the Utah exhibit” at the 1904 St Louis World’s Fair where they “sang several songs and distributed tracts.” 
Missionaries also sang in less-formal contexts like before priesthood blessings, baptisms, sacrament administration, and often before family/group or companionship prayer at night. [e] Sometimes they sang as part of proselyting visits; Sister Cluff seems to have been particularly fond of singing at visits.  Singing at visits correlated partially with bereavement and danger.  On many occasions hosts asked the missionaries to sing; sometimes neighbors came over specifically to hear the singing. 
Singing for audiences and host families took some gumption and sometimes they “almost made a failure of it.”  Brooks noted “the first meeting my comp and I had ever sang together in, we had quite a time of it” and then a little over a year later remembered the occasion.  Church leaders instructed the missionaries to “learn to sing, then be judicious in singing” and in some instances, “while walking along the road and out where no one could hear us, we sang or practiced some of the songs that were hard for us to get right.” 
In looking at singing patterns, the thing that stands out to me the most is how often the missionaries sang without an explicit purpose (at least as recorded in the diaries). Lines like “Spent the afternoon in singing and talking” and “we had a fine time talking and singing until Bed time” appear in the diaries more than any other type of reference to music. [f] In particular, when missionaries and/or church members got together, they often sang “the songs of Zion.” 
The “Southwestern States Mission” series (homepage) examines mission life in (mostly) Texas around 1900.
[a] Clark, 1901 May 07 Tue. Clark identifies “singing and prayer” as the “usual” opening three other times. When Jones writes that “we commenced our meeting in the usual manner,” I presume that he refers to singing and prayer. Clark, 1901 Feb 25 Mon; Clark, 1901 Apr 24 Wed; Clark, 1901 Jul 04 Thu; Jones, 1902 Jan 01 Wed.
[b] The basic model was: song – prayer – speaker – song – prayer. Common variations were to add songs before, during, and after the meeting and to have two or three speakers instead of one. I think the meeting format was generically non-Mormon: on one occasion Elder Brooks and companion sang for a local preacher, and the meeting followed the same general pattern. “Their preacher came Saturday night and stopped at the same place we did. … We went to the meeting house. The preacher asked us to sing. We sang a song for them. The preacher then got up and said he would like to hear us preach and asked if we would occupy part of the time. Elder Reed got up and gave them a speech on the Holy Ghost.” (Brooks, 1900 Jan 07 Sun). Some examples of multiple opening songs: “Just as we got through singing the last opening song Elder Decker turned sick and had to go back to Bro. Williamson’s.” (Brooks, 1900 Jul 22 Sun); “the people kindly consented to do the singing after singing I opened with prayer then singing again.” (Clark, 1900 Oct 29 Mon); “The congregation sang the first song. We sang next. Elder Huntsman opened by prayer.” (Brooks, 1900 Mar 11 Sun).
[c] Brooks, 1900 Mar 10 Sat. I have not attempted to count how often the missionaries sang versus the congregation singing; most of the entries are too vague to tell. Most of the time there is no explanation given, but Jones specifies a cold as the reason congregation sang. “As I had a very bad cold, we had the people sing for us.” (Jones, 1901 Oct 20 Sun); “we had a large crowd about 60 and they done the singing and Franklin Clark and Joseph Bond done the Preaching” (Clark, 1900 Apr 29 Sun); “After singing a song Elder Huntsman opened the meeting.” (Brooks, 1900 Mar 17 Sat); “The congregation sang the first song. We sang next. Elder Huntsman opened by prayer.” (Brooks, 1900 Mar 11 Sun); “After they had all got quiet we sang them two songs and then I began talking and continued for about an hour.” (Jones, 1901 Feb 14 Thu); “At 3 p.m. There was a large crowd and the house was full. My old knees were shaking like good fellows. We let the people sing for us. I presided.” (Jones, 1901 Mar 03 Sun).
[d] “On Friday evening we were surprised by receiving a telegram from Emma Ramsey, the beautiful singer from Utah. She was on her way home from the East, and desired the presiding Elder to meet her at the depot, which he did. She remained with us two days and nights, and we kept her busy singing while here. She went to street meeting with us and her beautiful voice attracted much notice. She left last evening. …” (Cluff, 1905 Jun 04 Sun). I found a few newspaper articles about Ramsey and a brief write-up about her mother at Keepapitchinin. (Also: Ramsey’s husband, George Morris—whom she married three weeks after the street meeting—became an apostle in 1954.)
[e] The “sacrament” in a Mormon context is the Eucharist or Lord’s Supper. Travelling missionaries administered and partook of the sacrament intermittently. In present-day practice, baptisms and sacrament administration take place in fairly standard, formal settings. In the early Twentieth Century, outside the Mormon Culture Region, practices were less consistent. Some examples: “After supper we sang a few songs and talked on the Gospel.” (Brooks, 1901 Jan 09 Wed); “Just before bedtime we administered the sacrament, sang a few songs, had prayer and retired for the night.” (Brooks, 1901 Mar 03 Sun); “after Supper we Set out on the Porch until Bedtime when he ask us in and ask us to hold Prayer with them we Sang a Song then I was mouth Piece in Prayer then we all retired to Bed” (Clark, 1901 May 02 Thu); “had Supper talked a long time on the Bible Sang a few Songs. had Prayer and went to Bed” (Clark, 1901 Sep 09 Mon); “We spent the day in study. At night we sang some, then retired.” (Folkman, 1900 Apr 20 Fri); “spent the day in talking in a General way until eve. when we sang hymns and at night held a sacrament meeting with Bro Shirley and family after which we had prayer and went to bed.” (Forsha, 1900 May 22 Tue); “We sang to them and held prayers with them before we retired to rest.” (Jones, 1900 Jan 26 Fri); “We talked with them until 10, then sang some songs and held prayers with them and retired to rest” (Jones, 1900 Mar 26 Mon); Talked until bedtime. Sang a few songs and had prayers.” (Jones, 1901 Nov 29 Fri); “Wednesday the 4 of July 1900 we remain with Brother Byers all day talking on the gospel and we converted one young man and he Said he was ready to be baptized we told him we was ready to baptize him So we went about one mile and found Some water then we Sang a Song at the water’s edge then Elder Bond offered prayer than Elder Clark led the young man down in the water and Baptized him When we got back Elder Bond confirmed him a member of the Church.” (Clark, 1900 Jul 04 Wed).
[f] Folkman, 1901 Apr 21 Sun; Forsha, 1900 Feb 28 Wed. I coded for various types of singing—for fun, for meetings, at formal celebrations, at proselyting visits, etc—but it was difficult to precisely distinguish some purposes. My coding suggests that 42% of the entries about singing or listening to singing were “for fun,” but I’d guess my error range puts the value between 32% and 52%. Overall, however, I am confident that the point holds: missionaries wrote about singing for fun or relaxation as much or more than for any other reason. One partial explanation is that routine singing was not recorded: they probably sang at almost every meeting but usually didn’t feel impelled to record the fact because the word “meeting” included the singing.
 “…Elder Clark arose and began to talk talked about one half hour when there was a man came in and Set down Soon he got up and ask me if I would Prolong my Remarks for a little while and wait until his family came he wanted his folks to hear me talk. I Set down and we Sang a Song and waited But his folks didn’t come So I arose and finished my talk” (Clark, 1901 Feb 28 Thu); “We did not commence until quite late as some of the people were slow about coming. We entertained what were there by singing a few songs to them. We commenced. I did all of the talking.” (Jones, 1901 Aug 14 Wed); “At night I went to one of the neighbor’s where I was going to hold a meeting alone as Elder H. could not come. There wasn’t anybody came out so we sang a few songs and went home.” (Jones, 1900 Aug 27 Mon).
 “…then we go to the Court House and Stay there until two more Elders came Elders Heywood and martindale after which we all went out by the Side of the house and Sang two hymns by that time there was a quite a crowd gathered Pres. Stewart took charge I opened By Prayer Elder Heywood done the Speaking Spoke on the Book of mormon” (Clark, 1901 Aug 23 Fri); “fine weather we commenced Tracting visited 35 houses then went on the Square by the Court House and began to sing Sang two hymns then Pres Stewart ask me to talk to the People I commenced and Spoke on the First principles of the gospel to a crowd of about 50 this is the Second time I have Preached on the Street Pres Stewart was the next Speaker Spoke on the organization of the church of Christ and its officers we talked about one hour then gave out notice we would hold meeting tomorrow in the afternoon” (Clark, 1901 Aug 22 Thu); “…also held a meeting upon the street, our first meeting. We sang two songs and the croud did not geather so we started to preach. There was a few people gathered round. We find street preaching is not what it is cracked up to be. We had an argument after the preaching.” (Folkman, 1900 Jun 04 Mon); “…then go to Greenwood and get ready to hold meeting on the Street after dark we obtained a gallery in front of a Store with a board for a table and a lamp one of the merchants to Put on it and laid the bible beside the lamp the meeting was called to order by Elder martindale after singing then Elder Clark arose to Speak to a large crowd of 80 People in Buggies and on the Platform and Some Setting on the ground it is the first time I have ever Spoke in the Streets the town has about 10 stores in it I Spoke alright and when I had Preached Some over a hour we closed by singing another hymn….” (Clark, 1901 Jul 30 Tue); “…then at 4 o’clock we go on the East Side of the Court House and Set our grips down and was going to sing and open meeting on the Street when the geneter [janitor?] and another man come to us and ordered us off the Court house property….” (Clark, 1901 Aug 28 Wed).
 Duffin, 1904 Sep 14 Wed.
 One example of many instances: “We walked into N. St. Louis today to call on a few friends. Mrs. Yoder, where we formerly roomed, was delighted to see and kissed us heartily. Her son and wife were there besides her two children and a neighbor lady so we sang and prayed and had a most delightful meeting. She asked us repeatedly to sing until we had sung six hymns, and they all appreciated it. Our singing is not of the kind to boast of, but there seems to be something attractive in it or we would not be invited again. We try to feel what we sing and so the Lord gives us strength.” (Cluff, 1905 Jan 04 Wed).
 Cluff provides several instances. See also: “…Were kindly entertained at dinner by a widow lady who had a short time before lost her only child, a young man 22 yrs of age. We sang a few hymns for her and talked consolingly.” (Duffin, 1899 Oct 27 Fri [as a travelling Elder before his reassignment as Mission President]); “…we walked over to Bro. Griffin’s where we spent the day. Very nice. They were feeling very bad over the loss of one of their dear little girls. They were glad to see us. Along about 4 o’clock we sang a few songs for them and held prayers with them and then, leaving them crying, we walked back….” (Jones, 1900 Jan 13 Sat); “We stayed with Bro. Speights all day, conversing with him upon the scriptures and having a good time. At night his wife began to get very uneasy about the things that were going around about us. She was afraid that someone would come there and take us and kill us. She said she hated to turn us away and she hated to have us stay, but we told her we would not stay there if she was afraid. So we ate supper with them and, going in the front room, we sang three or four hymns for them and, bidding them goodbye, we left, Sister Speights a-crying. We walked up with Bro. Huffman where we had a good time singing songs and talking, going to bed about 10 o’clock. (Jones, 1899 Dec 17 Sun).
 “In the afternoon there was a crowd of young people gathered at Mr. Glean’s. They had us singing for them. They seemed to like our songs pretty well.” (Brooks, 1900 Feb 04 Sun); “we called in a house that we had visited Before and they ask us to sing Some Songs while they got Some dinner” (Clark, 1900 Dec 29 Sat); “in the evening they ask us to sing Some of our Songs we Sang a half a dozen for them” (Clark, 1901 Apr 06 Sat); “At her request we sang two songs and prayed with her.” (Cluff, 1905 Jan 31 Tue); “We stoped with a Mr. Ben Whitaker. Their was a widow and two daughters come in to here us sing. We sang a few songs, after which we retired.” (Folkman, 1901 Jan 22 Tue); “After supper one of their neighbors came in and wanted to hear us sing so we sang them some songs and held prayers with them, then retiring to rest.” (Jones, 1900 Feb 12 Mon); “After we had eaten supper and the family had all sat down, they wanted to hear us sing some. We entertained them until 11 o’clock, when we all retired to rest for the night.” (Jones, 1900 Mar 25 Sun); “The family desired to hear us sing some. We had very bad colds but, notwithstanding, we sang them a good many songs, which pleased them very much.” (Jones, 1901 Mar 10 Sun).
 “Were granted the privilege of staying over night with Bro. Oakes. Had a good conversation. Tried to sing them some songs but almost made a failure of it.” (Jones, 1901 Jun 12 Wed).
 Brooks, 1899 Nov 19 Sun. “I had an appointment out at a school house a short distance from Bro. Thorne’s. It was the house Elder Reed and I made our first attempt to hold a meeting together and do the singing.” (Brooks, 1900 Dec 02 Sun).
 In a speech to missionaries in St Louis by Apostle George A. Smith, along with much other counsel: “Learn to sing, then be judicious in singing. Improve language. Be pleasant and cheerful, but avoid boisterous conduct and lightmindedness.” (Duffin, 1904 Sep 18 Sun); “While walking along the road and out where no one could hear us, we sang or practiced some of the songs that were hard for us to get right.” (Jones, 1901 Dec 26 Thu); “I practiced singing for a while in the parlor.” (Cluff, 1905 Jan 02 Mon); “This morning we all assembled in the office at 8 a.m. for singing and prayer, and we then practiced several songs for Sunday School….” (Cluff, 1905 Feb 12 Sun); “Yesterday evening while we were all assembled for singing practice in the back parlor, Pres. Duffin walked in, and quite surprised us, for he was not expected until next week.” (Cluff, 1905 May 20 Sat); “We have practices for Sunday School singing at 8 a.m., then prayer.” (Cluff, 1905 May 28 Sun).
 “…we concluded to remain in the school house until night. He gave us an invitation to come and spent the night with him. We spent the day very pleasant by writing, reading, and singing. We had prayers and went over where we had been invited.” (Jones, 1901 Jan 20 Sun); “…then going to Bro. Robertson’s I found Elders Heward and Ashby had got back. At dinner we had a nice stuffed chicken, which we all partook of; had a good dinner. After dinner we got our hymn books and sang songs for about two hours. The President then told us how we would travel and I was chosen to assist him and Elder Ashby.” (Jones, 1900 Apr 08 Sun); “…we went on to Williams Settlement here we Met Pres Hansen and Elder Pack. We went off to one Side and had a chat and Sang a few Hymns. Then Elder Jensen and Pres Hansen went to Village Mill and Elder Pack and I went on and got out an appointment to preach here….” (Forsha, 1900 Jan 29 Mon); “…in the evening we walked up to Bro. Cole’s and there met Elders Reed and Reucher. It was rather unexpected to us. We had a nice time that night singing.” (Brooks, 1900 Jun 13 Wed); “we meet the other two Elders and we travel together again we come to a clear Stream of water and we wash our clothes and bathe Stay until the clothes are dry no dinner today we go on a mile or two come in to the County I was assigned to work and Start to tracting we 4 Elders get together and sing a few Songs before we part then bid eacher [each other?] good bye the two others go into the next county to ours we go and Seek entertainment” (Clark, 1901 Jun 07 Fri).
 A few examples from Jones: “After supper we got to singing for them again. We sang everything we knew. They also sang a few and one of the boys played some music on the violin which sounded very good.” (Jones, 1900 Feb 02 Fri); “After supper some of the friends came in and we sang everything we knew to them and talked some upon the gospel.” (Jones, 1900 Feb 18 Sun); “We then took a walk down to Bro. Cox’s where we spent most of the day. One of their little boys was in bed with chills and fever. We sang songs until we were hoarse.” (Jones, 1900 Jun 01 Sun).