Ultimate multiinstrument scale reference! Perfect Scales is an advanced scale reference for professional and amateur musicians. It allows you viewing scales on 5 different instruments: - Piano- 6 string guitar- 7 string guitar- 4 string bass- 5 string bass Each of these instruments can be set up to have its own tuning. You can select any root note for your scale either on instrument or from the chooser window. All scales are played back via MIDI using the chosen instruments sound. The application is free,but does not include all scales and tunings. You always can purchase the full pack if you need to unleash the full power of the application. Really simple and intuitive UI. ATTENTION! I have tested the billing to be working OK. But in case something did go wrong on your device - please try clearing app data "Settngs-Applications-Manage Applications-Perfect Scales-Clear Data" and running the app with active network connection. If it doesn't help - contact me and we will figure it out.