Old tape restoration is a three-tool job, and the order matters: clean first, regenerate second, isolate third.
1. EQ the cleanup before Suno ever hears it. In any free editor (Audacity works), roll off the low rumble with a high-pass around 60-80Hz, cut a little harshness around 3-4kHz, and run light noise reduction on the hiss. Don't overdo it — you want 'cleaned tape,' not 'robot.' Export as WAV.
2. Cover it in Suno. Upload the cleaned tape and Cover it with a prompt describing what it SHOULD sound like: vintage blues, clean studio recording, harmonica-forward mix, warm. Cover re-performs the song without the tape damage. Keep style-influence low so it stays faithful.
3. Stems to feature the harmonica. ... > Get Stems on the Cover result. Now you can raise the harmonica stem, add a touch of reverb to just that stem, and rebalance everything in a DAW. This is where the solo goes from 'audible' to 'featured.'
4. If the solo is still buried, Cover just the solo section: trim the cleaned tape to the solo, Cover that 30 seconds with blues harmonica solo, front and center, expressive, then drop it back into your full mix.
What not to do: don't Cover the raw hissy tape and hope Suno cleans it — it'll interpret the hiss as an instrument (usually shakers, I wish I were joking). Clean first, always.
Good luck! Hank founder of SonorixPG