Final answer:
Promoters, advertising managers, and publicists are key players involved in devising the marketing plan for the release of a music album.
Step-by-step explanation:
The key players who help devise the marketing plan for the release of a music album typically include promoters, advertising managers, and publicists. These individuals are responsible for promoting and publicizing the album to attract a larger audience. However, album mixers are not directly involved in the marketing plan. They are responsible for mixing and producing the audio content of the album.