With your child's weekly piano lesson coming round (or violin or oboe or whatever), the inevitable debate rears its ugly head about "how often have you practised this week?". Sadly, classical music demands many hours of practice: even international stars seem to spend a terrifying proportion of their waking hours practising, regardless of how much native talent they have.

The answer to the question "how much practice do I need" depends largely on what standard you want to achieve. If you just want to learn a bit about the instrument and become competent to play a few pieces nicely, you'll get away with an hour or three a week. If you want to play in a band or orchestra without making a fool of yourself, you'll need more. But how much do you need to become a real expert, a world-class performer?

Dan Levitin, author of "This is your brain on music", has an answer: about ten thousand hours. Levitin is a neuro-scientist at the very prestigious McGill University in Canada (and former session musician, sound engineer and record producer) who has been studying the science of musical perception for many years. Ten thousand hours is equivalent to about three hours a day for nine years. If you're Mozart, Levitin reasons, you might well have started at age two and clocked up thirty-two hours a week (under the tutelage of a proverbially rigorous father), in which case you will have got to ten thousand by about age eight - the age at which Mozart wrote his first symphony.

Interestingly, according to Levitin, the ten thousand figure shows up repeatedly in scientific studies of many different walks of like, ranging from basketball players to concert pianists to master criminals. It seems that becoming truly world class at something takes around the same amount of time - which is probably a function of the length of time that the most motivated of your competitors are prepared to put in. Of course, just notching up the hours isn't enough: you have to ensure that you're fully engaged and concentrating.

So now you know what you're up against...

The book isn't exactly a snappy read for a non-scientist - it's fairly heavy on the brain structure and chemistry - but it's well worth the effort: full of fascinating insights into the effect that music has on us, and why different people react so differently to all sorts of musical styles. In spite of what is basically a rock'n'roll background, Levitin is encyclopaedic about many different types of music, from Western classical to rock and jazz and even Indian ragas.

Here's one snippet that particularly took my fancy:

All the available evidence is that music [...] has been around a very long time in our species. Musical instruments are among the oldest human-made artifacts we have found. The Slovenian bone flute, date at fifty thousand years ago, which was made from the femur of a now-extinct European bear, is a prime example. Music predates agriculture in the history of our species.

I've always felt that music is terribly, terribly important to me, without ever quite understanding why. Now, at least, I now that I'm in good company...

Finishing our Italian trip in Venice: here are a few sketches about what's going on.

Inevitably, I suppose, it's pretty much wall-to-wall Vivaldi. You'll find performances of the Four Seasons every day, sometimes in several different places; there are occasional concerts featuring his other works. A lot of the music is packaged for tourists rather than for sophisticated classical music listeners: we tried a typical event calling itself "Baroque and Opera" and consisting of one Baroque concerto (surprisingly not by Vivaldi) and a dozen or so favourite arias from Italian opera, performed by musicians in baroque dress. It was done very well, with decent singers and players putting some effort into it - far better than you might expect from the average tourist-oriented same-programme-every-day bash. By the way, Venice's architecture of narrow streets and stone buildings means that you can hear a surprising amount just standing outside the venue.

There's a lovely collection of antique musical instruments at the Chiesa di San Maurizio in San Marco, including various violins and cellos and more obscure instruments such as a Viola d'Amore (seven ordinary strings above the fretboard, and seven sympathetic strings below it), two Lyre Guitars (like a guitar, but with a resonator in the characteristic U shape of the lyre, and with three bass drone strings - a sort of 18th century version of the twin neck guitar used by Jimmy Page of Led Zeppelin), a rare keyboard hurdy-gurdy and others. We only saw half the collection, which is currently split between two venues; it's due to be reunited soon.

Not exactly classical but something of a musical curiosity is the contest that happens every night between the two (or sometimes three) cafés on opposite sides of St Mark's Square. The Caffé Quadri and Florian's each employs a quintet which plays various "light popular tunes" of the last century: anything from Brahms Hungarian Dances to tunes from West Side Story, Havah Nagilah and, bizarrely, Colonel Bogey. Each band has to outdo the other, which means playing louder, livelier and faster, with success measured by the rate at which people cross the square from one crowd to the other. On our nights here, Florian's was the clear winner, possibly more due to the attractive blonde violinist than to the merits of the music. Venetians tell the story that in his less misanthropic moments, Richard Wagner (who lived his last years in Venice) used to go and conduct the café bands on the square.

But our first prize for Venetian music went to the busker standing at the top of the Rialto playing various popular classics (Ave Maria, Jesu Joy of Man's Desiring etc.) on the oboe, with a CD for accompaniment. He was a small, quiet-looking elderly gentleman playing beautifully with the sweetest tone. What fascinated us was this: every child that went by was drawn to the music - the parents would stop to listen for a moment and expect to move on, and the children would drag them back to listen for just a little longer. We stayed for ages, a real treat.

This blog comes to you from the family holiday in Northern Italy, or more precisely from Desenzano del Garda on the southern shore of Lake Garda, surely one of the world's great beauty spots.

Can't get away from the music, though: on the way back to our hotel from a short kayaking excursion, my ear was caught (maybe assaulted would be a better word) by the unmistakable strains of "Casta Diva" from Bellini's Norma, sung at full volume over an enormous (and excellent) PA system which was up in preparation for Desenzano's yearly grand fireworks bash held for their "Ferragosto" holiday. The soprano, not, you'll be glad to know, dressed in full druidic priestess outfit, was singing her heart out into the microphone, face pointed firmly towards the lake and away from any possible audience. Only in Italy...

Actually, Norma has got form in these parts: by far its most famous interpreter of modern times was Maria Callas, who lived for several years in a house just by the Villa of Catullus at Sirmione. If property is all about location, location and location, the Villa of Catullus has to be the single most fantastic piece of real estate in the whole of Europe: set on cliffs at the tip of Sirmione, it commands a 350 degree view of the lake and the surrounding mountains, with only a thin spit of land connecting it to the mainland. It's all pretty much in keeping with Callas's image, and she has a small park named after her opposite the house.

A couple of pictures to give you the idea:

One of the joys (not) of running the Bachtrack website is the need to constantly keep cleaning the data. We try really hard to make sure that the lists of composers and works are in a consistent format, and as complete and accurate as we can make them, at least for the major composers. This results in tasks like this afternoon's effort of running through the thousand or so compositions by Schubert (extraordinary, given that he died aged just 31) trying to knock out all the duplicates and misspellings.

In the middle of this particularly tedious part of the job, one occasionally comes across some weird and wonderfuls. One of Schubert's very popular pieces is his setting of "Ave Maria", which I couldn't find anywhere in the official catalogues of his work. Turning to Wikipedia as usual, the answer turns out to be this:

The Schubert music is most often played these days to the words of the Ave Maria from the Latin mass. However, that's not the way Schubert intended it. The work is actually called "Ellens dritter Gesang" (Ellen's third song), and is a setting of a song from Sir Walter Scott's "The Lady of the Lake", which just happens to start with the words "Ave Maria". Some bright spark at some point decided to try it with the rest of the Latin prayer (probably an improvement - the Scott original is almost unbearably slushy to non-Victorian ears), and the idea obviously stuck!

The Schubertiade Festival's officially approved title is "Ellens Gesang III Hymne an die Jungfrau (Ave Maria)(Scott) D 839 (1825)". I think I'd better just leave it at "Ave Maria"...