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Have you listened to the Solo by itself to double-check that the sound is actually part of the solo track?



Yes. It is within the audio track.

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How did you create the solo? (For example, was it using F5 to mute/ummute various sections of a solo track or was it through use of the yellow Soloist button to generate the solo over a range of bars?)




Click on Soloist button.
Select Solo.
Click on Custom.
Enter start bar and number of bars.
Click on Generate.

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What's the Realtrack involved?



As mentioned, has happened on several tracks. This one is # 1513.