It was a big week for the Whitford family. First, Brad Whitford, the guitarist in Aerosmith, joined his bad boy bandmates for a free show on Commonwealth Avenue to hype Aerosmith’s new CD. Brad’s 87-year-old mom, Joyce, smiled throughout the eight-song set. That was Monday. On Thursday, Brad’s guitar-playing son, Graham, was on Jimmy Kimmel’s show performing with his band, Tyler Bryant & the Shakedown.