fix bug in selecting major or minor; add scale playback
fix bug in selecting major or minor; add scale playback

walterbender/musicblocks,eohomegrownapps/musicblocks,Hrishi1999/musicblocks,eohomegrownapps/musicblocks,Hrishi1999/musicblocks,walterbender/musicblocks,Hrishi1999/musicblocks,walterbender/musicblocks,eohomegrownapps/musicblocks