Does the sound quality from a CD differ from a direct iTunes download?

I love Les Mis 10th anniversary' sound track, so I downloaded it from youtube to my iphone. However, the sound quilty isn't that great, no matter how 'hq' the video is, it sounds abit muffed on my iphone.
The album is so expensive, £16, so I thought id buy a CD to download to my iTunes then to my iphone.
Will these tracks from a CD sound the same as those tracks provided by iTunes?

How to bypass school Wi-Fi on MOBILE?

So i'm connected to my school Wi-Fi on my phone (iphone 6 if that helps). However apps like Instagram, askf=.fm, and facebook don't load threw the app because they are blocked, how can i get around this but still be using the app, instead of using like a safari browser and a proxy.

How to add music to a video on my iphone?

I've made a video on my iPhone 4s. I want to add music to it from YouTube as IIm having a problem putting music on my phone. Is there any free app or site I can go to on my phone and music to it?

How does a human beat a computer in chess?

I heard that the computers can choose the best moves and see many steps ahead. Why bother challenging the computer unless you're a genius like Kasparov? And even he lost. So why do sites like chess.com have a computer player, and why do apps on iphone offer single player vs computer?

How to make my iPhone 6 Plus from Verizon wireless be able to be a hot spot for other devices?

I have unlimited internet with Verizon wireless because I'm grandfathered. I've had this line for 6 years. I want to be able to create a hot spot for other devices for examplle my laptop. I contacted Verizon and they have a hot spot plan but it's not unlimited. So my question is, can I jailbreak or do something to my phone so I'm able to broadcast a Wi-Fi signal/hot spot for other devices without having to pay Verizon wireless extra. And what are the disadvantages. Will my phone loose certain capabilities and features. And if it's possible can you guys let me know how.