For information and online purchase, please click on the links below.

Anton von Webern  (Phaidon Press, 1995)

http://uk.phaidon.com/store/performing-arts-music/anton-von-webern-9780714831572

The Messiaen Companion  (Faber & Faber, 1995, reissued 2008: edited by Peter Hill)

• Chapter on Messiaen's Instrumental, Orchestral and Choral Works to 1948 (including Les offrandes oubliées, L'Ascension, Quatuor pour la fin du temps, Turangalîla-symphonie, Cinq rechants)

http://www.faber.co.uk/work/messiaen-companion/9780571246441/

Selected Letters of William Walton  (Faber & Faber, 2002)

http://www.faber.co.uk/work/selected-letters-of-william-walton/9780571201051

http://www.amazon.co.uk/Selected-Letters-William-Walton-Malcolm/dp/0571201059/ref=sr_1_1?ie=UTF8&qid=1325595065&sr=8-1 

Liszt: His Life and Music  (Naxos, 2011)

http://www.naxos.com/catalogue/item.asp?item_code=8.558214-15

Currently out of print (available second-hand):

20th-Century Music  (UK: Heinemann, 2001; USA: Gareth Stevens Publishing, 2001)

Illustrated history for secondary school readers, covering classical music, ragtime, blues, jazz, musicals and rock, in 6 volumes:

• 1900-20: New Horizons
• 20s & 30s: Between the Wars
• 40s & 50s: From War to Peace
• 1960s: Age of Rock
• 1970s: Years of Excess (USA edition: Turbulent Times)
• 80s & 90s: Different Paths

http://www.abebooks.co.uk/

http://www.amazon.co.uk/