Hello,
Unfortunately, Zulu has not the option to remove background music/noise. Instead, you may want to try installing WavePad which is a sound editor program. It lets you record and edit voice and other audio recordings. You can cut, copy and paste parts of recording and, if required, add effects like echo, amplification and noise reduction. You can install the trial version using this link: http://www.nch.com.au/components/wpsetup.exe
You need to be aware that in WavePad you can remove frequencies but not specific sounds. For additional information, you can check out this link: http://help.nchsoftware.com/help/en/wavepad/win/equalizer.html
Regards.