How can i change the file size of my mp3 from 4,500 kb to 900 kb??what kind of application do i need?

Answer 1

If you have an audio program like "Music match juke box" you can "recode" the MP3 to a lower quality bitrate to reduce size, but you WILL see a noticeable drop in quality from a 4.5mb file to a 0.9mb one.