Give some stream of consciousness and then the answer. "I'll Keep Holding On" is a song composed by Mickey Stevenson and Ivy Jo Hunter and recorded by Motown singing group The Marvelettes, who released the single on the Tamla imprint in 1965. Peaking at # 34 on the Billboard Hot 100 (and # 11 on the R&B charts), the single returned the group to the top forty after a year recording songs that performed below the top forty. This was among the first A-side singles that longtime Marvelettes member Wanda Young sung lead on. Before 1965, the majority of the leads in Marvelettes songs had belonged to original member Gladys Horton. The single features a woman determined to win the love of an unknowingly conquest telling him that she'll convince him to love her "until my will to resist is gone". Her Marvelettes band mates Gladys Horton and Katherine Anderson egg her on with her ad-libbing "oh yeah / sho' nuff" in the bridge leading up to the chorus. The single was covered by British mod-pop act, The Action in 1966, released as "I'll Keep On Holding On". It then returned across the Atlantic in 1998 to be released on Mink Rat or Rabbit by the Detroit Cobras.

Based on this passage, who sings the song i keep holding on?
The relevant sentence in the passage is: "I'll Keep Holding On" is a song composed by Mickey Stevenson and Ivy Jo Hunter and recorded by Motown singing group The Marvelettes, who released the single on the Tamla imprint in 1965.
Therefore, the answer is The Marvelettes.