For patio drinks: the Rooftop Surf Club on top of the Strathcona Hotel. So fun! They have beach volleyball courts up there, a young crowd, and DJs. Go on Sunday, that's their big day/night.
For live jazz: Hermann's Jazz Club! Obvi! Seriously, try to catch my dear friend Rosie Bitts' Bitts of Tease variety show there, if you can. She and her band mix comedy, burlesque and jazz, in a caliber of show you would expect to see in a much larger city. A gem for sure.
For live music in general: see who is playing at Lucky Bar and at Logan's while you are there. Lucky is a downtown live music staple in Victoria, and they bring consistently good acts. This is where you would have seen Metric before they blew up. Logan's is in Cook Street Village, really close to downtown, and attracts an eclectic crowd that leans toward the hipster demographic. Victoria's little The Drive.
Have FUN, and feel free to PM me for more suggestions. I love my role as unofficial tourism ambassador for my city!