One of the first ways I learned to meditate/access different states of mind was a technique described as "overload trance" (IIRC). The premise was, listen to a piece of music, focusing on one musical component, then while keeping that focus, add another element, and another, etc.

It works best with pieces with a lot of ostinato (repetition/vamp) and Bach's Little Fugue in G minor was and is one of my favorites. Really fun to play too, though i get tripped up as soon as the feet get involved. Also, Utopia by Astral Projection (that whole album Trust in Trance 3 is great for this).

Bonus points to mentally visualizing something in time with the music (I like orbs whirling around like atomic orbitals). You can really tie up much of your mental processing this way and I find it much easier than traditional zen meditation, trying to bring focus back to eg. breathing.

Little fugue: https://youtu.be/ddbxFi3-UO4

Trust in trance 3 playlist: https://youtube.com/playlist?list=OLAK5uy_mHhgZDphEanJgP6zSz...