This week we’ve some pioneering, trailblazing Mahler with a dramatic twist, courtesy of a conductor who mentored Leonard Bernstein. Elsewhere, there are some disconcerting, dark sounds from a youthful German composer, and a supremely entertaining disc of highly theatrical vocal works courtesy of Paul Hillier’s immaculately drilled Theatre of Voices. Turn on, tune in and drop out while listening to Cathy Berberian’s cartoon-inspired Stripsody, and consider the very question of what constitutes music.

We are spoiled for choral choice in Britain. With the likes of The Sixteen, The King’s Singers, Polyphony and I Fagiolini just the start of the roster of talent, and an amateur choral scene of serious heft, the temptation is to look no further than the Channel for our choral kicks. Such is the growing presence of the Baltic nations however (and particularly Estonia, with its greatest musical champion, Arvo Pärt), that this rival tradition is increasingly making its presence felt. Greatest among a nation of choirs is unquestionably the Estonian Philharmonic Chamber Choir, who last night took us on a tour of their musical heritage.

UPDATE 2015: Four years ago, in January 2011, I wrote this article about the music critic and biographer Michael Kennedy's search for the missing portion of Elgar's life. It identified a Mrs Dora Nelson as the composer's mistress and mother of a lovechild, who might have influenced some legendarily enigmatic aspects of Elgar's compositional output. A new development opened when an Arts Desk reader contacted me, who had taken up Kennedy's and my requests for others to pick up this unsolved mystery.

As with pornographic films, what those who watch Glee really want is the money shot. There may be far fewer naked people – although the first episode of the second season did have lascivious shots of two shirtless (allegedly) teenage boys – but you still don’t really care about the bits in between the songs, which are all trite teen drama with a smart-mouth twist. No, the moment the plumber (geeky teenager) appears on the scene with his wrench (sheet music) is what gets the nerves tingling.

An awful lot of bad singing goes on in the name of Christmas. If it’s not the endless piped renditions of Slade and Cliff Richard, then it’s anaemic carol singers in every railway station and foyer. Each street corner becomes a concert hall (albeit one with exceptionally poor acoustics) and every passer-by an unwitting (not to say unwilling) audience member. Music becomes a commercial mood-board, a festive ear-worm to prompt charitable giving and personal spending in equal measure. How joyous then to escape the icy pavements and ambient noise for a few hours and celebrate Christmas with the ultimate musical professionals, The King’s Singers.

Christmas is coming, and prepare ye the way for a sledge-load of new music. It’s probably not just Stephen Cleobury’s annual commissioning of new carols for the King’s College Service of Nine Lessons and Carols that does it (though he must be partly responsible), but come Christmas every year there is a positive avalanche of new carols rumbling into the choral world. Whether broadcast to millions or sung to an audience of 37 in a tiny church carol service, Christmastide certainly gets the creative juices flowing among our composers.

McDonald's (the hamburger people) are rarely acknowledged for their contributions to the arts, but without them we may never have witnessed the meteoric rise of composer Eric Whitacre. When he was 14, he heard a casting call on the radio for a McDonald's TV ad, persuaded his mother to drive him into Reno, Nevada to join the throng of hopeful teenagers, and ended up making a brief appearance in the "McDonald’s Great Year" commercial.

To most the music will be more familiar than the name. Geoffrey Burgon, who has died, devoted only a minor portion of his career to composing for television.

He also wrote for piano, for trumpet (which he studied at Guildhall School of Music and Drama), for guitar quartet and all manner of chamber group. In 1991 he composed an operatic version of Dickens's Hard Times. Above all he composed for choirs - most notably his Requiem for the Three Choirs Festival in 1976.

Monteverdi’s 1610 Vespers are something of a musical enigma. Neither their true pitch nor order of movements, their origins, nor even whether they were intended as a complete sequence is known for certain, prompting scholar Denis Arnold to conclude that, “to perform it is to court disaster”. Such a grim augury however has done little to discourage musicians, and in this, their 400th anniversary year, Monteverdi’s Vespers have been ubiquitous.