Crystal recorder

When casting this spell the caster starts a crystaline spindel to spin.  as long as the caster concentrates the crystal will keep spinning, and while it does, all sound that can be heard at that location is recorded, and the crystal then becomes opaque with a small rune mark appearing at the top.  the change is perminant as is the recording (subject to the crystal not being broken).

once the created the crystal can then be used as a focus for illusionary magics to allow the sounds to be played back. the illusion spell used to play back effects how it works, minor illusion allows a quiet playback, phantasmal force - silent playback for the target of the spell, larger illusions can give more powerful volumes and control (for example fast forwarding and rewinding).

While the playback is illusionary, it is also verbatum, however people may not believe that it is real even though it will always be the same each time.