Here is a link to Larry Holcomb's dissertation that explains the whole history of the organization and has a complete index with all the songs.

http://libgen.io/search.php?req=A+HISTORY+OF+THE+COOPERATIVE+RECREATION+SERVICE&

I've been researching community singing movements in America and came across this thread. Also, yes, have been stumbling upon these song books in lots of people's homes and bookshelves for years. And I have a bunch of my own now too from "World Around Songs". From reading the dissertation, it seems Lynn and Katherine Rohrbough started advocating for recreation in the 20s and 30s, as "mixer" events mostly with young Christians, but eventually they sought to create much bigger bridges between different communities and cultures, to “promote a better understanding of people through their recreation” (Holcomb:149). This was pretty extraordinary considering the kinds of ideas circulating in the US during this time that claimed (and politically enacted policies asserting) the cultural superiority of Anglos; here were the Rohrboughs instead seeking to expose people to each other's folk traditions, dances, songs, puppetry, and folk plays with the hope that they might appreciate each other's character, beauty, intelligence. In 1926, their Social-Recreation Union had 10k members and that was just the beginning.

In Depression-era US, recreation was cheap and people had time and had become accustomed to spending money on entertainment; plus, these were "play party games" and not that devilish "dancing" with instruments and such ;). In other words, it was deemed wholesome by even the most suspicious Methodist ministers. They went on to do lecture-demo/"barnstorming" tours and have conferences with hundreds of recreation leaders throughout the US. In the 1960s they were printing out over 500,000 song books a year (with songs from over 56 countries). Their biggest legacy though is supplying numerous groups with their custom, cheap, copywrite-free songbooks (Scouts, YMCA, YWCA, 4-H, and the masses of public schools). Holcomb theorizes that the Cooperative Recreation Service fell out of fashion because Rohrbough refused to add new folk and popular repertoire (and so became less relevant) though Lynn said it was perhaps because of a lack of advertisement at conferences and no more of those lecture-demo tours that spread the gospel of recreation.

Again, now the company is "World Around Songs" and Old Time Musician Bruce Greene is keeping it going. Library of Congress also has the books and the recordings of a bunch of them (not all books were recorded).

An organization that was very much ahead of its time and is still extremely relevant as people need to appreciate each other and build intercultural understanding (and singing and dancing together sounds like a great way to do that :)!