ELO, Lyrics:
Mr. Radio.

Hello, Mr. Radio, you friendly station,
So glad of your company, your morning music,
My wife she ran away, she left our home,
And though you're here with me, I'm on my own.

Hello, Mr. Radio, you friendly speaker,
You played my request today, request to see her
Your voice comes riding home across the air,
You travel 'round the world, but still you're here.

I heard on the news today the world is no good,
But if she returns today mine could be so good
I look into the sky, your waves rush by,
The weather man has lied, it makes me cry.

Hello, Mr. Radio, do I disturb you?
Sometimes I forget my place, I seem to know you
I miss you when you close, you'll never know,
And when your programmes go, I'm on my own.

Jeff Lynne

From the 1971 LP, No Answer.

There are different recordings of an orchestra sampled at the beginning and end of Mr. Radio that is edited and played backwards. Both are samples of selections from some untitled pieces by Mozart colloquially called the "London Sketchbook" as performed by Sir Neville Marriner & Academy of St. Martin in the Fields in an August 1971 recording at Wembley Town Hall in London. The portion on the beginning of the song is taken from K. 15a-Ss-Devertimento in E Flat-2, K.15dd and the portion at the end is taken from K. 15a-Ss-Divertimento in E Flat-3., K.15cc & 15ff, but both are edited, flipped backwards and mixed into the song. The quadraphonic mix of Mr. Radio used a different classical piece at the song's end, which is as yet unidentified, but probably also one of the Mozart "London Sketchbook" recordings from 1971.
There is a very good recording of the Mozart London Sketchbooks performed by Anna Lena Leyfeldt (c.2014) on iTunes that contains K. 15cc, 15dd, and 15ff. I reversed these, slowed them down 10% and found the parts containing the phrases used in Mr. Radio. Very clever. Sounds symphonic this way, but it is solo piano at normal speed forward.