Nice post.
Soft music alone helps me to center. I enjoyed singing in our choir (taking a short break while ministering to my wife) because our hymns help to invite the Spirit by utilizing the Universal Divine Harmonics you mentioned. On the flip side I notice a withdrawing of the Spirit when listening to rock music.
I've been using meditative music on YouTube for some time for relaxation and sleep:
• https://www.youtube.com/watch?v=njHvGxZgTPk&t=14531s
• https://www.youtube.com/watch?v=rGCtEPnYzM8&t=9s
I also use similar music utilizing Binaural Beats at various frequencies - which do have some detrimental side effects for children and pregnant women that should be taken into account, and may cause headaches in others.
... and I also use natural sounds to help me sleep - especially a loop of ocean waves I access on my Kindle (no birds/instruments/etc); and less frequently rain/forest/babbling brook sounds.
I like your phrase "tuning in" to inner harmonies which I try to tune into when I get a chance to completely block out all sound and reflect.
A few poems I've written on the subject:
Of "Hymns" I Sing (pg. ix)
Though I sing out of time
and sing out of tune
My Heavenly Father
fills me with
His perfect love
and His spirit... when
I sing from hymns
divine
11/25/2012 r.11/26/2012
Gem in the Rough
I'd been in reflection
After reading my scriptures
In meditation listening
To a selection of random soft music
Concentrating mostly on my breathing
My heart beating its interminable beat
When I heard a sweet melody
From, most appropriately,
"Notes From the Tree of Life"
Accompanied by a still quiet voice
Beyond doubt by the Holy Spirit
I then realized
His simple Heavenly message
A spiritual gem to declare:
Christ Lives !Then was prompted to share it with you
12/12/2010
I Meditate
A mandala has imprinted upon my mind -
truly a wheel of fortune - one eternal round
Center - the tree of life with all its purity
Lehi's vision made manifest welcomes my thought
I reflect upon my burial in water -
upon my gift of fire - a reluctant saint
no longer I would aspire to the innocence
the faith of the humble man from Cupertino -
to feast upon His perfect love - life eternal
8/17/2017
Ta ! (short for tarradiddle),
tailor STATELY