EDM) Menno de Jong
https://soundcloud.com/mennodejong/menno-de-jong-live-at-luc... https://soundcloud.com/mennodejong/menno-de-jong-cloudcast-0...
Like other continuously mixed, mostly-ambient EDM but favors minor mode and affected arps that keep my brain occupied in it just enough to avoid distraction.
Japanese Drums) The Ondekoza, or any competent group
https://www.amazon.com/Haru-Ichiban/dp/B003P5RMBM
Pure rhythmic impulse, monotonic yet with remarkable complexity.
Classical) Glenn Gould's Bach, Mozart
https://www.amazon.com/Glenn-Gould-plays-Bach-Chromatic/dp/B...
Julian Bream, Bach, Lute http://www.barnesandnoble.com/w/julian-bream-plays-j-s-bach-...
Jonas Nordberg, de Visee et al, Theorbo https://itunes.apple.com/es/album/jonas-nordberg-visee-weiss...
Perhaps too much for deep flow sessions but extremely stimulating for more inspirational, breaking-down-the-problem "aha" moments.
When it comes to `classical` music, keep in mind that the term encompasses hundreds of years of evolution and dozens of genres or utilities that the music was composed to serve. For our purposes, we may want to stick to "salon" style solo or small ensemble compositions which were made by the masters with the express purpose of stimulating the logical and emotional mind. Church music and large symphonies for example are a completely different animal, but get unfortunately rolled in under this catch-all term.