Berman's Rainbow Dreamers

From Memory Alpha, the free Star Trek reference

Berman's Rainbow Dreamers was a 20th century Earth rock and roll group, popular during the 1960s.

Berman's Rainbow Dreamers performed at the Behr Theater in San Francisco during the Summer of 1967. (DS9: "Past Tense, Part II")

The poster featuring the performance appeared in the background during O'Brien and Kira's brief appearance in the 1960s. The date was originate from the script, which described the date as the "Summer of Love". The band name is a homage to Rick Berman.