What are all those numbers and letters at the end of classical music titles?

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If you wish to buy me a coffee, that would be appreciated:
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Beethoven Pastoral: Sir Adrian Boult with the BBC Symphony Orchestra recorded August 1, 1972, the Royal Albert Hall.

The Sad music is of course Elgar's Cello Concerto: [ Ссылка ]

Haydn London Op 104 [ Ссылка ]

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