The album contains a number of different musical styles and themes. "Nine Houses" is one of two intimate, religious songs, which the band would often reserve for after concert performances.[1] "Ruby Jean and Billie Lee" is another, written for their spouses, Ruby Jean Anderson (Seals) and Billie Lee Day (Crofts). The first verse is sung by Seals, and the second by Crofts, with both singing the chorus. Their children (Lua Crofts and Joshua Seals) are mentioned in the chorus.
Diamond Girl peaked at #4 on the U.S. album charts.[3] Its title track "Diamond Girl" reached #6 on the Billboard Hot 100 chart in the summer and #13 in Canada. The follow-up single "We May Never Pass This Way (Again)" attained the #21 position late in the year (#33 in Canada).