Novosibirsk is considered to be the foremost city of Western Siberia. It attracts many people of all ages, origins, and interests. It's no surprise then, that one can find any kind of entertainment, food, and activity there.
There are a lot of open air cafes on Lenina square during summer and it's just a nice place to walk around and to meet people. Another good way to meet people is to go to a jazz or rock club, this kind of music is very popular in Novosibirsk.
Novosibirsk people like jazz and blues music, you can often hear it playing in some specialized clubs, pubs, bars, clubs, etc ; the city is even considered to be one of the three big jazz music center in Russia (others being Moscow and St. Petersburg). Also there are many young people in Novosibirsk, so dance music is quite popular there.