Changing Pitch without changing quality?

[tila123]

Hi, I'm working with Audacity 1.2.6 and I try to change some instrumentals I have to a different pitch but every time I do, it distorts the song and it sounds like you're listening to it through a wall. The beats aren't as crisp as the original and it lowers the volume a tad too, actually. So I was just wondering if there was a way to change the pitch without changing the quality? or to make the quality better once the pitch has changed? Or if you recommend a different program that'd be able to help do what I need to?

Thank you so much in advanced for your time and input in any responses.