Greetings Bil,
Rio's OPERA HOUSE is under renovation and there's no classical concerts scheduled during your period in the city.
Rio's MUSICAL CULTURE - Brazil has no less than 178 rhythms - is more into Samba, Gafieira, Bossa Nova, etc. As an excellent option of what we could define as jazz infused samba, check Vinicius Piano Bar in Ipanema.
CULTURAL/ HISTORICAL things: the whole city is an opened air art gallery. There are some tours being offered covering Santa Teresa & Downtown which would perfectly fit in your request and overwhelm your expectation. Fell free to PM me for more consistently information.
MUSEUMS: 1) MAC - Contemporary Arts' Museum located in Niteroi (other side of Rio's bay) is a master piece of Oscar Niemeyer and its architecture is a piece of art itself! 2) The NATIONAL ARTS MUSEUM is opened with half of its capacity, offering either the 18th or the 19th Brazilian Arts' Collections. 3) CASA DO PONTAL is a sweet museum offering naïf Brazilian Art - kind of distant of main Rio's sites but a lovely side trip. 4) I myself like very much CHÁCARA DO CÉU - a tiny museum located in Santa Teresa.
J