There is some potential in this concept for a few emotional scenes, but I can’t see it holding up over the course of a full length feature.

The stakes are too low and the obstacle too obscure.

Technically speaking the MC’s goal is to win the singing contest, but the event that motivated him to win it is his wife asking him to do so. Failure, a highly likely outcome considering the nature of such reality TV shows, means disappointing his wife that makes her the stakes character. He stuck with her for years through her sickness and did try to win the show, which means she can’t say he doesn’t love her or isn’t willing to go to great lengths to please her. If she were to say he hadn’t done enough for her, it would make her nasty, self centered and inconsiderate.

Disappointing someone who loves him and appreciates him for his efforts will result in a none event, yet if she is a nasty person disappointing her is really no big deal (if not welcome) and therefore the stakes are low in the concept as a whole.

Further more if indeed he is or was a singer, he has all the necessary tools and skills to win the contest. However if he had never tried singing professionally then his challenge is that much more great, and if he were to win or place in the finals, his triumph more significant.

As mentioned above, unless it’s his bucket list and there are other obstacles for him, I don’t believe this is a strong enough concept for a feature.