Aerosmith singer Steven Tyler made a surprise appearance in Nashville and performed two songs before the audience was ushered out for the next show. Tyler was in the crowd Tuesday at the Bluebird Cafe watching four Nashville songwriters perform in the round: Mallary Hope, Phil Barton, Lindsey Lee and Marti Frederiksen. The small, 90-seat venue is where many country singers first got their break and where many established artists often stop by to play songs or listen. Frederiksen invited Tyler to sing ‘‘Jaded,’’ which Frederiksen co-wrote. Tyler then jumped on Lee’s piano to belt out the band’s power ballad ‘‘Dream On.’’ Afterward, Tyler told The Associated Press he had never performed in a room that small and he was in Nashville to write songs.