There are a bunch of music festivals this Memorial Day weekend, and a bunch of people camping or vacationing somewhere else. THEREFORE, you have the city to yourself, and it's ripe for the taking. For instance, tonight is Sophisticated Mama at Havana. The night has built quite a nice following, which nowhere near resembles what you'll find at the club on a weekend night. Estimable DJs Nitty Gritty and Sad Bastard spin soul goodies from the 1960s and '70s, throngs of industry people drop in, and Getting Down is done by all. (Havana, 1010 E Pike St, 323-2822, 9 pm, free, 21+)