Why are there so many downloads? Each different kalimba, or each different tuning of the same type of kalimba, will have different notes, and hence can play different songs. Each will have different strengths and weaknesses, each will need its own music, and each will have its own books or downloads. The exception: music written for the Alto kalimba can also be used for the lower 15 of 17 notes of the Bb Treble kalimba as well as for the upper 15 of 17 notes of the D Treble kalimba which both have tines painted in a way that is compatible to the Alto kalimba.
Almost all of these downloads utilize Kalimba Tablature, a graphical representation of the kalimba extending up the page with musical notes plopped on the tines that need to be played to accomplish a particular melody or song. Most of these downloads include PDF files of the tablature, KTabS files, and at least some MP3s so you can hear how the songs go. Some downloads are waiting to be books, and are in the form of a single PDF file which gives you the web page from which you can download MP3 files for each song.