Why is it...?

Well. The contestants put together and choose their own song arrangements. This comes down to their own musical chops.


When they do a medley it is probably arranged by professional composers who work for the show. They probably also help the contestants a bit more with the vocals. The composers are prosfessional and they probably give out the solo parts based on each contestants vocal ability.


Song choice isn't just about sound. Its also about image. For example Jason Castro always picks songs that go with his folkish laid back image and unique voice. It works well.

My guess is that the rest of the group helps to cover the flaws in the voice and as they all know a bit a key notes they are better able to cover for each other.

It may also be due to the fact that the soloist gains confidence from knowing they are not alone but rather have a strong backup/accompaning team. (lol)

Part of it could be that they are in a group setting so it is a little more comfortable for them even if they do not know the song as well. Also when you are singing alone sometimes you get so nervous you just sing your song knowing you messed up, or were not your best and hope no one notices. For me, I have done Karaoke, and sang solos in choir, etc. but I don't think I could have ever wanted to do it on National TV like that and be judged.