Top (Also Cheap) Audio Editor?

[syncbesseCymn]

I demand to take down a few of music-on-hold for the office PBX program. It seems like great majority of these business procedure work as it:

1: Greeting (nearly five to eight seconds) while fluffy music plays in the background.
2: Fluffy music gets louder for nearly 10 seconds
3: Sales or data pitch whilst fluffy music quiets to background.
4. Repeat steps 2 and 3.

Is there any ease of use audio editor that I can utilize to do that?