Thank you so much for this!
“Somewhere Over The Rainbow” seems to attract people who like to experiment with it. In addition to your theremin example, there is the ukelele version by Israel Kamakawiwoʻole. And then there is this hard rock example by Toby Swann, which I’ve always liked:
Nega by Brazilian Tania Maria. Its jazzy and laid back. Love this song.
I grew up in New Zealand through the 70s, 80s, and 90s. There are a ton of NZ songs that nearly nobody on this site will have heard before but which I really like still.
Like this one from Peking Man, this one from Dave Dobbyn and Margaret Urlich, and this one from The Crocodiles with Jenny Morris.
César Franck, Prélude, Fugue, Variation. It’s an organ piece, which might explain why it’s not very popular, I prefer the piano arrangement. Listen to this hauntingly beautiful, melancholy melody.
https://www.youtube.com/watch?v=4WsJtUWlR3s
Remo and The Barbwire Band is a band that has played on St Martin, Dominica, and Uganda since 2000. We see them most years at The Blue Martini, a bar in Grand Case, St Martin.
True story. [spoiler]One year we were in Grand Case for their Carnival; having a great time, dancing and drinking in the streets. There were bands everywhere and everyone was happy.
We were approached by a guy who, back home would be assumed to be homeless or a derelict. He was very drunk (as were we) and he had the remains of his lunch and dinner all over his threadbare clothes. But he was happy and so were we.
I bought him a drink and he joined us in dancing. He pointed out some points of interest in Grand Case and introduced us to several locals. Everyone seemed to know the guy and several people called him “Mr Mayor” which I thought meant his last name was Mayer.
He suggested we check out The Blue Martini, so we went in. The bar was crowded, but he yelled, “drinks for me and my new friends” and the bartender stopped what he was doing and took care of us. I tried to hand the bartender a twenty, but he told me the mayor took care of us. Barbwire was performing (this was before Remo added his name to the band) and we had several more drinks, all paid for by “the mayor”.
After the band was done playing that night, I met Remo. He explained to me that “the mayor” was actually really the mayor of the town, and a truly great guy.
Earlier that night in Grand Case we ran into Jimmy Buffet who also was falling down drunk. He was on Anguilla and had come across the water to Grand Case for the Carnival.[/spoiler]
Trees of Mystery in ‘Mooks On Parade’ is one of my all-time favorite albums. The band recorded this absolutely brilliant album and broke up shortly afterward, never seeing any real success.
I listened to César Franck’s piece and enjoyed it (which I may have mentioned in the temporary forum before the move, but I guess that place is gone). 
I’ve been checking out a lot of Krautrock in the last months, especially Amon Düül II who made great music. There’s a bonus track on their album “Wolf City” from 1972 called Mystic Blutsturz that sounds eerily like early 90’s British triphop, especially the beats and also the whole atmosphere. It definitely must have been influenced by Jamaican dub just like triphop was, but almost 20 years before. I know no other music of the time that sounds even close.
Macedonian zurta - haven’t heard Makedonska in years.
Ravel
Sheherezade - 2. La flûte enchantée
(French lyrics and English translation)
Miroirs No. 5, “La Vallée des Cloches”
Debussy
Nocturnes for orchestra
Apparently well known in China as it’s covered a lot, 普通Disco (Ordinary Disco). I first heard it as a cover by Annie, then listened to the original and most recently heard it an audition song on Produce 101 China
The song is about the creation of Duresori and is about how the members initially didn’t want to form the group, then began to enjoy being together and the solos (Jo Ah Reum, Kim Seul Gi, Im Ha Nui) are a lament about their struggles.
Seul Gi’s aria is based on Pansori, traditional Korean storytelling music and Ah Reum and Na Nui sing: “It can be hard, it can be painful. But this is a path we should go on.”
The coda ends the song on an high note as everyone rejoins and sings about how they bring happiness to others with their singing.
This 2011 formation of Duresori features three amazing arias, (I may have these wrong), alto, tenor and finally an amazing soprano by Seul Gi (sorry, don’t know the other girls names) that’s worthy of the angels. Sady the solo reprise by Ha Nui is missing and as testament to the power of her voice, has never appeared in any future version of the song.
Duresori is the official choir of the Korean National School of Performing Arts and the choir changes as students graduate. But lately, a mix of current? and former students have been making appearances as Duresori.
Carl Stalling’s musical soundtrack for Warner Brothers cartoons. Lots of people have heard it and can recognize it, but it takes on a whole different feel when you listen to it without the visuals.
Korean indie bands.
Mukimukimanmansu is one of my favorites. Here is one of their videos:
Raising my baby son, we had a DVD of the Eric Carle stories including “The Very Hungry Caterpillar.” The DVD had animated versions, together with a beautiful soundtrack by Julian Nott, the composer of the music for the Wallace and Gromit episodes.
I was really impressed, and return mainly to listen to the music from time to time. Some highlights from the album:
Very Hungry Caterpillar
https://www.youtube.com/watch?v=75NQK-Sm1YY
Papa, Please Get the Moon for Me
https://www.youtube.com/watch?v=sGqAw7UM6qo
I see a song (classical animated music video)
https://www.youtube.com/watch?v=aDCIETZnCbw
First to pop to mind: Kula Shaker, a late 90’s alt-pop band from England who infused much of their music with Indian sensibilities, but keeping it rocking. Sitars, tabla hand drums, reeds, the whole shebang. Actually, that describes their '98 album Peasants, Pigs & Astronauts as that’s the only album of theirs I’ve ever owned, but I recall when I tripped across in Tower Records in San Francisco and listened to nothing else for at least a week or two.
Happy Rhodes - Summer
https://www.youtube.com/watch?v=5R8pgPChsJs
Pansori 판소리 (pan=open space or gathering place, sori=song/signing or sound) - Well known, loved and highly appreciated in Korea, but deserving of recognition elsewhere.
Duresori that I posted about above is a mix of a Western choir and pansori, which is usually performed by a single singer .
Every Korean knows at least one version of the pansori Arirang, Almost all versions of Arirang are some lament of a woman about her love that can’t / won’t be with her.
Bump just to let anyone interested know about a recent find.
Borgström’s Violin concerto, particularly the second movement.
This concerto was apparently recently discovered after being forgotten for a century. The second movement has a beautiful lyrical theme, worthy of any romantic composer.
https://www.youtube.com/watch?v=jdoyJzjWxJA
(the theme starts around 16:00).