"Ruby Blue" is an avant-pop, jazz and glitch album that mixes electronica with early-20th century vocal jazz, an interest of Herbert's. The instruments, primarily brass and woodwinds, are layered over sampled noises such as alarm clocks, a water cooler, hairspray and helmets. Murphy's vocals were described as a combination of "a less-pained Billie Holiday and a less-sheltered Doris Day". She cited OutKast's 2003 double album "Speakerboxxx/The Love Below" as an influence, stating that "it was experimental, it was soulful and funky". The album's lyrics are based on her romantic relationships with Brydon and then with Henwood.