Will songs from itunes sound better than YouTube?

[G-Ziss]

When I am in my car, I connect my iphone to the radio using blue tooth and then I play songs through the YouTube app.

If I buy the songs from itunes and play those versions, will they have a better sound quality compared to YouTube?

Also, how does itunes song quality sound compared to an audio CD?

I am using an iphone 6 plus if that makes any difference.

 

[Shirasaki]

iTunes version is generally better than YouTube version. But iTunes version is not always worse than CD version.
To stretch the thing a little bit, iTunes version has the same audible sound quality as CD version if songs are just some random pop music. But if songs contain lots of details, iTunes version would probably be a bit worse than CD version.
Theoretically speaking, CD version is always better than iTunes version as iTunes is lossy while CD is lossless. But if we just listen to the song, most of the times we cannot immediately distinguish between them. So this is more like personal preference than something can actually affect the experience.

 

[thats all folks]

iTunes encodes to 256kbps AAC. that is considered "indistinguishable" from CD for general use (about a 6 to 1 compression ration). Whether that is true, is a choice you would have to make for yourself. YouTube encodes to a large variety of codecs and qualities. So the for best source uploaded to YouTube, from my experience connecting through a browser on a desktop, will sound terrible at 320p or less. will sound acceptable at 480p, and will sound as good as YouTube will offer at 720p or above. results may also vary on mobile devices/apps depending on what YouTube chooses to stream to you.

but YouTube is not a closed system like the iTunes music store. so the first hit to quality is what happens at the submitter's end. if the source is a VHS of a TV broadcast, captured to an MPEG-1 and then uploaded, it will always sound bad. but even starting with a pristine source, videos are compressed before upload to YouTube and then re-encoded by YouTube before being made available for playback so I have believe that iTunes store sourced files will always be less compressed overall.

also, using Bluetooth, adds another compression step.

but considering that a car is a noisy environment and your focus should be more on what is going on outside, than inside, maybe it's all not such a big deal.