Our song search of course is just of the songs in The Music Box on this website.
There are many other song search engines available. Here are a few good ones
UT Song Index based at University of Tennessee library in Knoxville contains 50,000 songs and searches 1500 published collections as well as many recordings.
Secondhand songs can be a bit confusing in terms of how they group around slightly different variants but is especially good for identifying the recording history for a song with links to YouTube videos similar to The Music Box. You sometimes have to hunt around to find the "master list"...