Loved this game more than I can put into words, but I'll try! I thought I was playing a basic platformer, decided to keep playing because I'm a music theory nerd and your idea to build the score up by LITTERALY building a band was making me smile. Then I got to the first level where you have to utilize the different-height jump mechanic and HOLY SMOKES, the "jump" in complexity threw me for a loop and made me realize this thing is so much more than a basic platformer with a neat music mechanic! Every level after that was so well thought out and utilized the mechanics to their fullest extent, I can totally see myself playing a full version of this if you add some story and more levels, hell, I'll even pitch in and voice the dwarfs for you!
The intro to that jump size difference is my one critique, I had no idea what I was doing wrong and a tooltip explaining the mechanic would've been appreciated.