Read a sound file (may be this is a music file) in matlab and detect some frequency bands that you want and develop an FIR filter using both sinc function and fir1 function. Analize your filter response uzing fvtool (For example magnetude response and zeros). Dont forget to chose a window type. Save the filtered sound in wav files. Develop at least 2 filters, for example one low pass filter and one band pass filter.