Garageband sustain piano

Ok, I'm experimenting with Garageband and I'm using the musical typing function, where I can play piano, or any other sounds using the keyboard. When I play the music back, the piano doesn't sustain like I want unless I hold the tab key to employ the sustain. However, I shouldn't have to hold the tab key to listen to my music, lol. Does anyone know how to apply sustain permanently to this?

Did you ever find a solution for this? Thanks.