Scratch #1 (Shift+1): Enable scratch sample recording for sample position one.
Scratch #2 (Shift+2): Enable scratch sample recording for sample position two.
Scratch #3 (Shift+3): Enable scratch sample recording for sample position three.
Scratch #4 (Shift+4): Enable scratch sample recording for sample position four.
Scratch #5 (Shift+5): Enable scratch sample recording for sample position five.