This study investigated whether the tempo and timbre of background music influenced responses to radio ads. In Experiment 1 (in addition to a no-music control condition), slow- or fast-tempo background music was superimposed over the same ad. The slow-tempo music treatment produced significantly higher levels of ad content recall compared to the fast-tempo music treatment. Musical presence (slow- and fast-tempo treatments combined vs. no-music) significantly reduced levels of ad content recall. In Experiment 2, when three versions of digitally produced background music timbres were superimposed over a no-music version of another ad, results revealed positive main effects of timbre congruity upon recall of ad content and affective responses to the ad. Copyright © 2006 John Wiley & Sons, Ltd.