The album's lone guest is Rachel Benbow Murdy, band founder Mike Doughty's ex-girlfriend, who supplies a vocal on "Janine." Doughty had Murdy go out to a payphone in Sheridan Square in New York and improvise a long, meandering song into their answering machine. Recorded a year before the Ruby sessions, Doughty and bass player Sebastian Steinberg recorded the tune at the avant-garde jazz club The Knitting Factory during the daytime, when the club was closed, with club soundperson James McLean. McLean put a mic on the answering machine, which Doughty had brought to the session.
Ruby was named after Ruby Froom, daughter of record producer Mitchell Froom--a frequent collaborator of Ruby Vroom producer Tchad Blake--and singer/songwriter Suzanne Vega.
The album was recorded at Sunset Sound Factory in Hollywood, Blake and Froom's usual haunt--a storage room near the studio's lounge was filled with vintage keyboards and road cases filled with toys--whistles, baby rattles, children's toy xylophones. Many of these ended up in the songs, such as a train whistle played by Doughty on "Uh, Zoom Zip". This was in keeping with Tchad Blake's spirit of maverick experimentation, which included sticking a binaural head-shaped microphone in front of Yuval Gabay's drumkit, sticking a mic in a car muffler, called "the Bone" and sticking that in the drum booth as well, and having Doughty improvise wild, yelling ad-libs on "Casiotone Nation," singing into a cheap amplification system called an Ahuja that Blake bought in India. The speaker was essentially a huge bullhorn atop a stick.