Looking at the music of Dutch rock band Focus, started in the late sixties by Thijs Van Leer (b /31/03/48) with Jan Akkerman (b 24/12/46). Van Leer still performs and records under the name today (official site here). Akkerman's site here.
Focus are not known for their vocals but the songs they have sung feature several languages.
1. English (Why dream, Happy nightmare, Black Beauty, etc, etc)
2. Dutch (O Avondrood, Hamburger Concerto, Flower Shower)
3. Latin (Round goes the gossip, Hoeratio)
4. French (La Cathedrale de Strasbourg)
5. Spanish (Santa Theresa) [on the Japanese Focus X]