There are currently 48 total known song-scrolls in the Realms with 47 being readily available for purchase and 1 being part of a quest prize treasure. Only one person in the realms at a time can be studying a given scroll (if they are online you will see their name show up when you READ the scroll, otherwise it will just inform you it is being studied). Once they are memorized, the bard can play them from memory and the scroll passed on to another bard. If you do not complete memorization of the scroll on the first try, there is an approximate 10 minute timer until you can study again. Only Bards can learn song-scrolls.
NOTE: Just like gwething, you cannot use prepositions [to, of etc]; so with any song beginning with a preposition, you must EXCLUDE it and go to the second word.
This list is comprehensive as of August 2010.