After inserting a quarter and pressing player start, the original arcade version of Arkanoid shows a brief introductory story where the mother ship Arkanoid is destroyed by a yet-unknown attacker, and the spacecraft "Vaus" is jettisoned, only to be trapped in warped space. During the cut scene, the Start Demo jingle plays.
The song is rendered on the YM2149. It is number 0A in the game's internal sound test.
Since the NES port doesn't have the opening cut scene of the Arcade, the Start Demo jingle plays at the title screen after you press start.
The song is rendered on the Nintendo's RP2A03. It is track 1 in the NSF file.
Full transcription by Nick Kalata. (NES version)