[quote:35807]Is it possible to change key of the audio samples without major distortion (appleloops also)?
It really depends on the audio material you are working with...and how far the change is from the original key. Have you tried using the sample editor's Time & pitch machine?
If working with apple loops the transposition feature works better when the loop is at it's original tempo - or very close.
[quote:35807]And, is there shortcut to set several regions at the same size and velocity at once in piano roll editor (logic studio)? [/quote]
Yes! I think you means MIDI events or notes right, not regions?
1. if you want to set the size and velocity of the MIDI notes within multiple regions shift click on them and double click to open the piano roll.
2. Press Cmd-A to select all the notes
3. Hold down Shift-Option and begin adjusting the one of the note edges. All notes selected will become of equal size.
4. To change velocity to equal amount select the velocity tool and hold down option while dragging on the selected notes.