From the Amphibian Abstracts blog: "Even though I hadn't used background music before in a game before, it was very easy to add. Playing a sound when the frog jumps was also simple.
But what about playing a sound when the frog lands back on the ground? Not as easy.
First, the simple sounds. For background music, I used "Ouroboros" by Kevin MacLeod (http://incompetech.com). The jump and landing sounds were public domain from FreeSound.org. I added them all to my asset pack file. I gave the background music the key bgmusic1, the jump sound the key jump, and the landing sound the key thud."