Hums was a deliberate attempt by the band to record in a variety of styles. They composed and played in the pop, country, jug-band, blues and folk styles. It would ultimately end up to be the last full project by the original lineup. It was recorded in New York with the exception of "Lovin' You' which was recorded in Los Angeles.
The album managed to spawn four charting singles for the band, including the No. 1 hit "Summer in the City". "Rain on the Roof", "Nashville Cats", and "Full Measure" also appeared on the Pop charts, all but the last making it to the Top 10. Bobby Darin had a Top 40 hit with a cover version of "Lovin' You". Johnny Cash and June Carter Cash later covered "Darlin' Companion" in 1969 on Johnny Cash at San Quentin. Principal songwriter John Sebastian said of "Nashville Cats" — which made No. 8 on the Billboard Hot 100 — "We thought our version would cross over to the country market. It never did. So we're always kind, gee, well I guess that tells us what we are and what we aren't." Flatt & Scruggs took "Nashville Cats" to No. 54 on the country charts as a single.Dolly Parton covered "Lovin' You" for her 1977 album Here You Come Again.
Hums of the Lovin' Spoonful was re-released in 2003 on the Sundazed label with bonus tracks consisting of four demos, instrumental tracks, and alternate versions/mixes of songs from the album, along with extensive liner notes. It was also released on CD along with Do You Believe in Magic? in 1995.
In his Allmusic review, music critic William Ruhlman wrote of the album "An emphasis on the parts of the album is a way of describing it as more a loose collection of disparate tracks than a unified effort, despite Sebastian's hand in all the compositions and his lead vocals on most of them. This was by necessity, but also by design, since Sebastian and co. went into the studio trying to sound completely different each time. They often succeeded..."