FRIDAY: >> The city’s free concert series follows MC Hammer with a rare appearance by salsa legend Willie Colon, 7-9 p.m. at Woodrow Wilson Center. >> President Nixon’s White House counsel John Dean will be at Politics and Prose to discuss his book, Broken Government, which examines “the institutional damage he believes the Republican Party has inflicted on the executive, legislative, and judicial branches of government during the Bush administration.” 7 p.m. He’ll also be…

>> Touch Acoustra performs every Thursday at Bossa Bistro and Lounge. The group combines the improvisational elements of straight ahead jazz with a diverse set of musical influences.

>> Twins Jazz continues its tribute to the sound of Philly with performances by pianist Neil Podgurski. Podgurski brings a group to Twins both Friday and Saturday night. Contact the venue for details.