Q: which sound editor software is best for reducing the noice from an audio + removal of music from a song?
A: Try Audacity (just Google it). It has a noise reduction function but this only works if there is enough of just the noise you want to remove somewhere on the track. Be aware that the greater you set the noise reduction the more it affects the quality of the recording. By removal of music I assume you mean the removal of an instrument. If so, it can't be done. If the music is already in wav or mp3 format you cannot separate the individual instruments. That can only be done if the music is in multi-track format. That is the way in which the songs are recorded initially then they are mixed down to stereo. Each instrument or vocal is recorded on a separate track which can be manipulated or deleted by the engineer before mix-down. For example Audacity is a multi-track recording program so you can record multiple separate tracks. These can be edited separately. If they are saved in Audacity's own format they can be opened later and changed but if exported as wav or mp3 they can't.