Model Name: MacBook Pro
Model Identifier: MacBookPro14,1
Processor Name: Intel Core i7
Processor Speed: 2.5 GHz
Number of Processors: 1
Total Number of Cores: 2
L2 Cache (per Core): 256 KB
L3 Cache: 4 MB
Hyper-Threading Technology: Enabled
Memory: 16 GB
In Metro 7.3.71 with 1 audio track and 3 MIDI tracks, all tracks looked and played from Metro as expected. I exported the MIDI file in type 1 and discovered an extra MIDI track. This turned out to be MIDI from the audio track. In Metro, clicking in track Outputs I changed the output from the audio track to a MIDI output. Metro warned I had audio in the track but changed anyway. Then the audio disappeared from that track in track and Graphic windows, and the MIDI data appeared in that track in the track and graphic windows. Edit/Data Extract/Cut all notes and other midi info from the track. I reimported my audio track and was back in business. I can't say for sure how the MIDI got into the audio track. There was lots of it! Jeremy, if it would help, I have screen shots of the track, Graphic and event editor windows.
Thanks
Victor