In his reissue notes, Pete Welding called In the Wee Small Hours “the single finest collection of mood songs ever recorded” with an intimate narrative focus tailor-made for the early LP era. Sinatra was just a year into his prolific Capitol period on his ninth studio album, and Nelson Riddle’s arrangements—emotionally direct, never flowery or saccharine—framed his voice with subtlety as he delivered what would become definitive versions of these timeless songs by Alec Wilder, Harold Arlen, Richard Rodgers, Duke Ellington, and more. Four of these—“Glad to Be Unhappy,” “Can’t We Be Friends,” “I’ll Be Around,” and “Dancing on the Ceiling”—featured a smaller ensemble within the band, giving the music room to breathe and highlighting the sublime taste of players like guitarist George Van Eps. Much like Ella Fitzgerald’s interpretive albums for Verve, Sinatra’s Capitol outings did a great deal to codify the Great American Songbook in the mid-20th century—In the Wee Small Hours chief among them.