The sales of singles grew by a record-breaking 76 per cent per cent to 631 million units, beating the previous record set in 1979, during an era dominated by punk and vinyl.

Growth was almost entirely accounted for by a surge in demand in the United States, the market in which iTunes is most popular. ITunes allows fans to buy songs individually from albums for the first time. However, the trend did not represent good commercial news. Price pressure on single-track sales — which cost 99 cents or 79p on iTunes — means that the market is worth just over $1 billion (£525 million) worldwide, down 25 per cent compared with five years ago.

At the same time, lost album sales — the result of the boom in downloads — helped to depress the global market for recorded music, which was down 3 per cent at $20.8 billion during 2005, according to the International Federation of the Phonographic Industry.