has the song ever been sung in live concert?
Yes during the  the Jacksons' Destiny Tour
Don't Stop 'Til You Get Enough
Michael Jackson performed this song on The Jacksons' Destiny Tour on the second leg, as well as the Triumph Tour. It was also performed on Jackson's 96-97 HIStory World Tour as part of the "Off the Wall Medley" along with "Rock with You" and "Off the Wall". 
how much is michael jackson off the wall album UNANSWERABLE when was this album released? August 10, 1979 what critical responses did the album receive? It was ailed as a major breakthrough for Jackson, while receiving widespread critical recognition, along with praises, from major music publications under which record label did the album release? Epic Records which are some of the famous songs of this album? Don't Stop 'Til You Get Enough and Rock with You who composed the first song? Michael Jackson
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Don't Stop 'Til You Get Enough [SEP] Live performances
Michael Jackson performed this song on The Jacksons' Destiny Tour on the second leg, as well as the Triumph Tour. It was also performed on Jackson's 96-97 HIStory World Tour as part of the "Off the Wall Medley" along with "Rock with You" and "Off the Wall". Jackson would have also performed it on the This Is It concert series as part of the "Off the Wall Medley", but the shows were cancelled due to his sudden death.