Purchased Ablelton 9 live yesterday and also purchased cues from loop community. Watched the videos from loop community and got the click and cues going with no problem. Added in MIDI track and a grand piano from ableton. Worked fine. Added in another MIDI track and a guitar from ableton. No sound. Tried several things. Nothing. Suggestions??? I'm very new to using MIDI and ableton. Any help would be greatly appreciated. Thanks!!!