Extend (エクステンド, Ekusutendo) is a jingle that plays when you either get enough points to earn a free life in Arkanoid, default set to 20,000, or when you collect the Player Extend (P) capsule. The jingle was composed by Hisayoshi Ogura. The official title comes from the Legend of Game Music 2: Platinum Box album.
The jingle is rendered on the YM2149. It is number 10 in the game's internal sound test. There is another, similar jingle at number 0D, it's slightly longer and ends with a thud. The purpose of this similar sound is unknown. It may be entirely unused, it may have been a competing demo tune that was dropped, or it may be played in a very rare circumstance, like when you have too many lives.
The song is rendered on the RP2A03. It is number 3 in the NSF file.
Full transcription by Nick Kalata. (NES version)