There are many ways to write music. Whichever way you choose the most basic element remains only one: the instrument.
If you choose to use a piano and a violin, you will never be able to play rock. If you choose to play a distorted guitar, you’re probably off in a different direction.
However, most of us, think only about music by using instruments, and not sounds in general. I myself have written music using mainly electric or electronic instruments. What happens, however, when you start using sounds from nature?
This is where it gets interesting. Every sound around us can be used in a musical setting. There are three main ways to do that:
1) Use a sound as an oscillator in a synthesizer
2) Sample it a use it rythmically
3) Use it as it is
Out of the 3 choices, I am currently used the 3rd one. It is a very artistic choice. I am taking urban samples, from highways and airports to train stations, and I am using them as the background noise of my tracks. It is strange, how the ambient noise can "fill" the sound of a musical piece. It’s also very strange, how non-musical sounds can be used in a musical setting.
The two best sources of ambient samples I have found are these: The free sound project and a plugin called Speakerphone Cabinet by AudioEase. You can download some urban noise from the free sound project and add it into the background of your track. You can also use noise as an introduction or as an outro to your track.
Of course, this is my way of doing music. Aphex Twin, has created an experimental masterpiece, called Bucephalus Bouncing Ball, where he uses a sampled bouncing ball as a special rythmic effect
On the other hand, Native Instruments’ Absynth has many programs that use experimental sampled oscillators. I have used one of these on my track "Gabriel". It’s a sound that uses a tibetan voice. I leave it to you to find which of the sounds it is
Anyway, once you allow ambient noises into your tracks, you’ll enter a new world of inspiration. Matthew Herbert creates pieces that are mainly focused around sounds he has recorded himself. Check out "Yesness" for example, where it has used countless recorded "Yes" from people. The possibilities are endless.