GoldSrc games play tracks from physical Audio CDs overriding media mp3 tracks

[hobokenn]

[Nimble-Bubble]

I believe this is meant to be a somewhat intended feature. Since Half-Life was initially released on CD, the soundtrack was formatted as audio tracks on the disc. When the game wanted to play music, it would play the audio track from the disc through cd play and related methods like target_cdaudio and trigger_cdaudio. Later versions of Half-Life include the audio files with the game (usually as .mp3 files), but may still support the ability to play CD audio tracks (depending on the version or engine; Source made cd play obsolete).