Yes, it's a bit strange. I'm guessing we are overlooking something simple. It's most likely a setting.

Let's try this.
Playable RealTracks are Hi-Q instruments. Assign a Hi-Q instrument to a normal midi track. The track labels are yellow for midi tracks. If the pathway is correctly set, you should hear sound. If not, then we can assume we've narrowed it down to the Hi-Q pathway or settings.

I suggest doing the test with a new song project. Open BIAB. Select any midi style. Type S9 into any measure of the Chord Sheet to load the style's demo SGU chart. Test to ensure the song has loaded and plays. With the test set up, assign a Hi-Q instrument to any style instrument other than drums. This is done by right clicking on the channel, Select Midi instrument (Patch) and Hi-Q instruments are first on the list.

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BIAB 2025:RB 2025, Latest builds: Dell Optiplex 7040 Desktop; Windows-10-64 bit, Intel Core i7-6700 3.4GHz CPU and 16 GB Ram Memory.