Matlab Sound of Music
Matlab can be used to create signals that can mimic the sound of a musical note, which can be used to play the tune of a song. Each note of a song is created by individual sin waves at a frequencies for each note. The following line of music has three different notes, C D and E.
Each of the three notes in this piece have their own unique frequency. C has a frequency about 261.63 Hz. D and E notes are created by multiplying the C note frequency by a factor to create a new note. For D the factor is 9/8 and for E the factor is 5/4.
A sine wave when played without an envelope would create a constant volume sound. However, when striking a piano key the sound is at first loud and then fades as time goes on. To replicate this effect in matlab, the sine wave can be multiplied by a negative exponential coefficient. The following code creates the song above in matlab.