Every good musician should be able to comfortably play and improvise in a variety of keys. There is a wealth of famous songs that have lead sheets written for them, but that doesn’t help you if you can’t play over the chords in the lead sheet, which can often be from the Melodic Minor or Diminished scales! When jamming with other musicians, you can often be called on to play in keys that you are not used to playing in. What do you do if the band decides they are going to play in A Flat major, and you only ever play in C major or B flat? How do you practice for this sort of occasion? This app allows you to select a scale or mode and then start a metronome that will cause a new key symbol to be presented every bar. Practice improvising over the changing scales and eventually you will become comfortable playing in any scale, mode, or key! You can customize what scales appear, how many beats per minute the metronome counts, and how many beats until the bar ends and a new chord symbol appears. There is also a lesson section which has short descriptions of each of the scales that can be practiced in the app, in case you don’t know how to play them. This app currently has all chords and scales in the Major Scale, Melodic Minor Scale, Diminished Scale, and Whole Tone Scale. Future updates will contain populaar chord progressions like the Twelve-Bar Blues, Rhythm Changes, and 2-5-1s, and the ability to add exotic chords and scales you want to practice that are not preprogrammed into the app.