Anyway, I want to introduce some other bands in the same vein, who aren't as popular well-known yet. First of all:

Alceu Valença e Geraldo Azevedo - Quadrafônico (1972)
This record has the very same kind of child-like and fun feeling to it as Os Mutantes did, and, well, it's great. Alceu Valença, who is now an elderly gentleman, is apparently popular in Brazil today, both as a musician and as a actor. Geraldo Azevedo has recorded a number of records as well, a few of which I will be posting here over the next few days - with Zé Ramalho and his cousin Elba Ramalho.
Recommended if you like good music! Click here and listen.

Umas & Outras - Poucas e Boas (1970)
Don't ask me about this band, because I don't know much, and the internet won't tell me much either (googling tells me that the Brazilian version of some movie with Sean Penn in it is entitled Poucas e Boas, but I don't think there is any relation). All I know is that one of the three members went on to play in Quarteto em Cy, and that this record is more of that soothing, life-affirming music that Brazil apparently is full of - and that the band has some relation to a tv-show at the time.
Umas e Outras was, the band was dissolved in 1971, three young ladies, who sing sweet Gal Costa-like songs. Very naïve and innocent sounding. The opening track is entitled Abrace Paul McCartney Por Mim, "Hug Paul McCartney For Me" - imagine three Brazilian girls singing a song about that on a record from 1970, and you can probably imagine how sweet this is.
Click here and listen.
Important: if anyone knows anything interesting about these records, please leave a comment. The same goes for those who download and listen to it. Please let me know if you're out there.