Suno v4 is the model that put AI songwriting on the map. Vocals - both melodic and rapped - are genuinely impressive, and the song-structure understanding is at frontier.
The trade-off: less precise control than Stable Audio. You're prompting song vibes, not arranging stems.
Licensing improved with v4 - Pro tier outputs are commercially licensable, with stem export added late in 2025. Pricing is per-minute and competitive.
Verdict: the vocal music champion. 8.7/10.