Isso só acontece nos jogos que usam audio stream aqui tem uma lista
https://www.hardmob.com.br/threads/306324-Lista-de-jogos-de-GC-que-usam-audiostream
No antigo loader do Wii que rodava via dvd que era o GC loader 0.2 e também no WODE esses jogos também ficavam sem música, por isso eu comprei na época o Eternal Darkness e o Star Fox Adventures, e eu estudava comprar o crazy taxi e o wave race.
Pode pesquisar que você vai ver que esses jogos no WODE também ficam sem música.
https://www.gc-forever.com/wiki/index.php?title=Audio_Streaming
Wii
Wii drive replacement modchips usable on GameCube such as WKF/WODE will be affected by audio streaming titles due to the design on the modchip.
(need validation:) Since these modchip types rely on media such as SD or USB and not the DVD drive, there is no hardware conversion of the ADPCM audio to PCM audio. The modchips do not include on-board hardware conversion nor the ability for firmware based conversion. Without this audio, the GC will display error messages. To work around this issue, the audio stream is disabled by providing a successful (completed) return command to the GC to prevent error messages and in game crashing.
Currently WKF and WODE are not able to send audio streaming data to the GameCube using SD, HDD, USB media respectively. To regain ability to correctly play these audio streaming titles with a drive replacement modchip, a dvd drive must be utilized in conjunction with the modchip in bypass (flat) mode....or using Swiss to boot a dvd