From the LMH pocket dictionary:

el·e·va·tor mu·sic (n.):  1. Tunes with a certain synthy-sounding, jazzy aesthetic, described by some as "cheesy" or "bad." 2. The kind of music you'd hear if you were on hold for the doctor's office. 3. Anything that sounds like, or is, "The Girl from Ipanema." 4. The jam.

NOTE: If it wasn't addressed in any subsequent episodes, Rob made an error by playing