instrumental

这首曲子有一个很棒的乐器间奏部分。

This piece has a beautiful ___instrumental interlude.

他的建议对项目的成功起到了关键作用。

His advice was ___instrumental in the success of the project.

理性常被视为实现目的的工具性手段。

Rationality is often treated as ___instrumental to achieving one’s ends.