If you are recording Audio from Midi, then extending sounds in Midi by lengthening the value of the notes in the Notation or Piano Roll Windows can work for certain instruments such as horns, but not for pianos, guitars, vibes, etc. You can,however in these cases use the Midi Controller 64(Sustain) to switch sustain on and off. CC64 Value 127 = ON, CC64 Value 0 = OFF.