Rock legend Bob Dylan will release a new album in 2015, he has confirmed, after he unexpectedly put out a cover of a Frank Sinatra song.

The announcement comes ahead of the commercial release on Tuesday of "The Basement Tapes Complete: The Bootleg Series, Volume 11," a six-CD set of restored recordings of Dylan's 1967 sessions with his ensemble The Band.

A note in the boxed-set says simply: "'Bob Dylan, Shadows in the Night,' New album coming in 2015."

There was no further word on the nature of the album, which would be the 36th studio recording for the now 73-year-old rocker who maintains an active touring schedule.

In May, Dylan hinted at the album by releasing on his website a picture of himself with the title, "Shadows in the Night," behind blue bars in the style of a record cover.

Dylan also at the same time put out a cover of "Full Moon and Empty Arms," a pop song based on a work by classical pianist and composer Sergei Rachmaninoff that was most famously performed by Frank Sinatra in 1945.

The song drew speculation that "Shadows in the Night" would be an album of cover songs by Dylan.

Dylan's last studio album, "Tempest," was released in 2012. The musically ambitious title track is a 14-minute account of the sinking of the Titanic that uses traditional Irish melodies.