My dad was a fan of the Canadian rock band Rush. Ever heard of them?
Yes, but i don't know much about them.
Rush was made up of Alex Lifeson, Geddy Lee, and Neil Pert.
When was this?
They formed the band Rush back in 1968. 
Are they still together or too old now?
January 2018 that the band was not going to continue.
According to the RIAA, Rush ranks 86th with sales of 25 million units in the U.S. Although total worldwide album sales are not calculated by any single entity, several industry sources estimated Rush's total worldwide album sales at over 40 million units as of 2017. The group has been awarded 24 gold, 14 platinum, and 3 multi-platinum albums.
Rush has received nominations for seven Grammy Awards. The band has won several Juno Awards, won an International
Rush discography
Rush was a Canadian progressive rock band originally formed in August 1968, in the Willowdale neighbourhood of Toronto, Ontario. For the overwhelming majority of its existence, the band has consisted of bassist, keyboardist, and lead vocalist Geddy Lee, guitarist Alex Lifeson, and drummer and lyricist Neil Peart. The band achieved this definitive form when Neil Peart replaced original drummer, John Rutsey, in July 1974.
The band released its eponymous debut album in March 1974. Since then, they have achieved 24 gold records