The kazoo-sax is Suno's brass weakness showing — exposed solo horns get the synth treatment. The workaround is arrangement, not just prompting.
1. Be specific about the horn: tenor saxophone, breathy, smoky jazz club beats 'sax.' For sections: three-piece horn section, trumpet tenor-sax trombone, tight stabs.
2. Bury it slightly. Horns that sit IN the mix sound real; exposed solo horns sound fake. horn section supporting, blended in the mix — counterintuitive, but a slightly-back horn reads as real while a front-and-center one reads as kazoo.
3. Humanize the description: breathy sax, natural vibrato, expressive phrasing — breath and vibrato words fight the synth tone.
4. Short stabs over long solos. A 4-bar horn stab sounds convincing; a 32-bar sax solo exposes every weakness. Write horn parts like a horn arranger: punches, answers, fills — not concertos.
5. Exclude: synth brass, MIDI horns.
6. Real horns fallback: for the money moment, hire a session player on SoundBetter/Fiverr for $30-50 to play your 8 bars over the Suno track. Cheapest realism upgrade in music.
Good luck! Hank founder of SonorixPG