"Song Sung Blue" is a 1972 hit song written and recorded by Neil Diamond, inspired by the second movement of Mozart's Piano Concerto #21. The song was released on Diamond's album, Moods and later appeared on many of Diamond's live and compilation albums.

It was his second No. 1 hit on the Billboard Hot 100 chart in the United States, after 1970's "Cracklin' Rosie", and to date his last. The song spent twelve weeks in the Top 40. In addition, "Song Sung Blue" spent seven weeks at No. 1 on the adult contemporary chart. It also made the pop chart in the United Kingdom, reaching No. 14 on the UK Singles Chart. The song has become one of Diamond's standards, and he often performs it during concerts.

"Song Sung Blue" was nominated for two Grammy Awards in 1973, Record of the Year and Song of the Year. Both awards that year were won by Roberta Flack's rendition of Ewan MacColl's song, "The First Time Ever I Saw Your Face".

Diamond described "Song Sung Blue" in the liner notes to his 1996 compilation album, In My Lifetime, as a "very basic message, unadorned. I didn't even write a bridge to it. I never expected anyone to react to "Song Sung Blue" the way they did. I just like it, the message and the way a few words said so many things."

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