When you say "change pitch", what do you mean exactly ? What are you trying to achieve ? Do you intend to record an entire song and then speed it up or slow it down or do you intend to record certain parts at a different pitch before putting it back to normal ?
There's a difference and depending on how you do it, both can be totally unnoticeable. If you've recorded a song but you think it's a bit too fast or a bit too slow, by changing the pitch up or down by a semitone (say, C to C# or Eb to D) I doubt whether anyone would be able to notice. If you went up or down by a tone or more (say, from G to A or G to F), then you'd possibly start to sound too chipmunk-y or stoned out of your gourd.
On the other hand, if you're recording elements at a different pitch, it can make a great difference. If the song you're recording has been tracked but the vocal part is making you strain because it's too high, going down a semitone will probably become well comfortable for you or whoever to sing in. Or you can have just two vocalists doing backing vocals, recorded at different pitches (speeds), say 5, and when put together they can sound like an incredible choir. Or if you want to nail a guitar, mandolin or keyboard solo, you can slow the recording right down so the pitch is LLLLOOOOWWW and work out the notes. If you choose the right notes in the right place at the right pitch and do your solo, when you go back to normal speed, you'll sound like a fast twelve fingered octopus genius that Hendrix or Chick Corea took lessons from. And people will gasp at such dexterity and no one will know what jiggery pokery has taken place.
You ask if there are songs here that have had the pitch changed, but they all could. Unless someone has gone for the obvious chipmunk/stoned ranger effect, you'd probably never know.
So the capacity to change pitch can be a useful feature. Personally, I wouldn't even entertain the thought of having a DAW or multitracker that didn't have this feature.