O is for… Ornament
To create distinctive sounds using only limited waveforms, chip musicians often use ornaments, which are additional quickly-played notes used for embellishing the main melody - you might know them as grace notes.
A common chip music ornament is the octave 'blip' whereby the note starts one octave higher then drops down to the correct octave a fraction of a second later, giving a bright 'punch' to the start of the note. Usually, chip music software makes it easy to define and apply ornaments to your existing melody, so you don't necessarily have to program them manually. Ornaments can also be useful for adding accents to percussive sounds.
No ornament
Octave-up blip
Octave-down blip
O is also for... OverClocked Remix
OverClocked Remix is a website that specialises in remixes of game music, from the ‘80s up to the present day.