Typical 303 line made with rubber duck. Bottom end rolled off and a bit of filtering. Makes a nice driving sequence. Try automating a filter with some delay. 8 bars long,150bpm.
This is a sample of a metal kitchen mixing bowl. The first note (b, not perfect b) is unpitched and recorded as is. The following notes are the original note pitched up 1 semitone each time to achieve a 13 note scale b to b.