There's Disney's animated musical film [Hercules][1]. The protagonist wasn't (until the end at least) a mortal man, but had **super**human strength, and spent a lot of the flick training with a professional "**hero** trainer" [Philoctetes][2], and in musical bits.

It wasn't billed as a "superhero" movie at the time, but in the 20th century that didn't exactly exist as a defined genre yet, and being a "Disney movie", complete with musical numbers, was probably considered a bigger sales driver.

His origin story in the movie is very similar to Wonder Woman's in the 2017 movie. Both got their powers through being children of Zeus, but were sent to Earth to live as morals. (Arguably, the original Thor movie had a similar setup as well).

The movie's theatrical release was in 1997.


  [1]: https://en.wikipedia.org/wiki/Hercules_(1997_film)#Plot
  [2]: https://en.wikipedia.org/wiki/List_of_Disney%27s_Hercules_characters#Phil