I recommend three bars in Harbin downtown for you.
1)Diao Guang Shi Ke
Address: 92 Fuhua Sidajie, Nangang District
The cost is very cheap. Many Chinese university students go there.
2)USA Buck
Address: 166 Zhongyang Dajie, Daoli District
I like the beer and the cocktail. Many foreigners go there.
3) Si Ka La
Address: 3/F, Swan Hotel, 95 Zhongshan Lu, Nangang District
The performance is very good. I like their band.