Well, Rockstar Mooney got the clubs, about nearest bars, you guys can check out the Park Qin (@ShuYuan Youth Hostel, a place to meet & talk to people, local and travellers), Belgium Bar (good beer), and other bars along the city wall near the South Gate. there are 我是丽江 (tinny but cute), and some jazz places there.
for good live bars in the east side of the old city (not far from the bell tower), check On The Road 在路上酒吧 and 光圈 Bar (not easy to find, better make a call)
or bars a bit far, like
King Garden Bar (beautiful yard, classy deco, but I don't remember they serve cocktails), and Green Molly in Gaoxin.