Cheap Sound Bytes
I learned in High School that I could turn headphones into microphones by sticking them in the Mic In slot on a tape player. I also learned I could record some singing, play it back on one side of a dual cassette player and record harmony over the top of the first part on the record side of the cassette player. I did my first solo four-part harmony recording with my College Roommate's dual cassette player and some cheap headphones. It sounded like someone singing through a set of tin can and string 'telephones,' but for me it was still a ground-breaking technique for creating cheap music.
Later down the road for a wedding gift, we got a dual cassette stereo with a Karaoke feature which allowed me to use cheap microphones (that were actually built as microphones) to record four-part harmonies by myself. This time it sounded like talking through a wrapping paper tube instead of a tin can telephone. But nonetheless, it was still a fun experiment for me.
Not quite 10 years later, I came across Audacity, which is a free, powerful sound recorder/editor which allowed me to transfer the tape to the computer, remove the noise and enhance the sound (as well as possible given the poor quality of the raw material.) Below you can hear a sampler of my experiments (I will apologize in advance...believe it or not, this actually contains the "best" snippets I had):