Since I have a piano recital tonight, I have had music on my mind all day long. Seriously, I have practiced this piece for several weeks and now whenever I hear a piano, I think about the Maple Leaf Rag. Anyway, I have been thinking a lot about the chords in the song and how the different notes react with each other to make that chord sound the way it does.
I have found some videos that show how different notes react with one another. Both of the examples compare C to every interval all the way up to the next octave. For both examples, see how the waves react when C is played with C# versus how the waves react when C is played with G because there is a big difference between the sounds of those chords. This first video is of sound in sine waves, which is most likely the most common and recognizable wave shape.
This next video is similar to the last one, however, instead of sine waves they use saw waves. Saw waves are cool because they sound more futuristic/robotic and are extremely recognizable. A notable example of the use of saw waves in music is on Pink Floyd's "Welcome to the Machine" off of their record, Wish You Were Here. Saw waves are also prevalent in a lot of modern music, especially a lot of rap such as the beginning of Kanye West's "Father Stretch My Hands Pt. 1" off of The Life of Pablo right after the sample. (Very recognizable part of the song).
I hope you enjoyed listening to noises for a few minutes. It is quite interesting how the different frequencies of the notes react with one another when put together!