has it been recorded by other musicians as well?
Yes, "the Miracles".
I Heard It Through the Grapevine
Producer Norman Whitfield recorded "I Heard It Through the Grapevine" with various Motown artists. The first known recording is with the Miracles on August 6, 1966, though there may also have been a recording with the Isley Brothers, or at least Whitfield intended to record it with them; however, a track has not turned up – some Motown historians believe that a session may have been scheduled but cancelled. 
who sang i heard it thru the grapevine Gladys Knight & the Pips by whom was it composed? Norman Whitfield and Barrett Strong was it a part of any album? No, the first recording was released as a single. by whom was it produced? Norman Whitfield what is the song about? The lyrics tell the story in the first person of the singer's feelings of betrayal and disbelief when he hears of his girlfriend's infidelity only indirectly "through the 'grapevine'".
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I Heard It Through the Grapevine [SEP] Motown recordings
Producer Norman Whitfield recorded "I Heard It Through the Grapevine" with various Motown artists. The first known recording is with the Miracles on August 6, 1966, though there may also have been a recording with the Isley Brothers, or at least Whitfield intended to record it with them; however, a track has not turned up – some Motown historians believe that a session may have been scheduled but cancelled. The Miracles' version was not released as a single due to Berry Gordy's veto during Motown's weekly quality control meetings; Gordy advised Whitfield and Strong to create a stronger single. The Miracles version later appeared on their 1968 "Special Occasion" album, and a slightly different take, possibly from the same session but unreleased, appeared on the 1998 compilation album, "Motown Sings Motown Treasures".