“Downtown Baby / Lay Down Susie” is a song Aerosmith performed live in at least one known occasion (University of Maine, Orono ME, September 30th 1973).
While the live performance sounded well rehearsed by the band, Tyler failed to deliver any real finished lyrics (other than the fan-guessed-title of “Downtown Baby / Lay Down Susie”), still, it may very much have been a song the band was considering for the first couple of albums and could have tonally fitted either. Its a basic blues tune with some improvised vocals, and interesting guitar and harmonica solos.
There is virtually no information about whether or not this song was actually recorded for their debut album. When band members were approached and asked about it during the 90’s, they failed to recollect any details about it, so, if it was written by the band, even they (understandably) forgot about it. If it’s an original Aerosmith song, or if it an un-clear cover remains an unsolved mystery.