In pictures: Broadcasting House at 75

The BBC had its own internal libraries, with one holding reference books and another housing gramophone discs.

About three million records, CDs and cassettes have now been archived in the music library at Broadcasting House.

The BBC's commitment to music was evident as early as 1927, when it took over the Proms, which faced financial problems.

These concerts, which are still running today, were inaugurated by Henry Wood in 1895.