Most of us think we know a piece of music if we can hum it. Classical musicians are not so lucky. They have the complexities of the score to grapple with, and not only must they do justice to the notes, they must give a performance that amounts to an interpretation.
Later this month, BBC Radio 4's Practice Session looks, as its title implies, at the practice and learning processes of three musicians, including flautist Philippa Davies. The programme will follow her as she prepares for a Wigmore Hall recital in June, including learning by heart a piece by her late husband, Paul Reade.
Choosing which pieces to perform from memory is a tricky process, but as Davies says, "Whether or not I perform with the score does not change the way I learn a piece. I always learn it inside out. The process begins by sitting down without my instrument, so that I'm seeing and imagining the work without thinking about technical problems. Once you have the hang of the piece, you work at it to reveal where those technical problems occur. That's a process of repetition, getting the piece into your fingers. As you get into that process, you should be practising without the score, so that your ears help your fingers, rather than just using your eyes to follow the score. The eyes are fine, but they tend to deafen the ears."
Yet while the learning process may be the same, dispensing with the score inflects the performance itself: "There are pieces which really fly if I play them without a score. Debussy's Syrinx, for example, has a certain atmosphere, and you want the audience to feel that you're inside that atmosphere, in another realm as it were. And then there is the virtuosic aspect, as if you've gone on to the platform naked. It does mean that you go through that thing of, 'How does it start?' But you've learnt your ways through the problems, not just at a technical, digital level, but in terms of the work's form, its structure."
Not the least important aspect for a flute player is controlling the breath so that the music emerges with no ungainly gulps and gasps: "I suppose I'm a singer manqué, and I think of the flute as a voice. For a singer, there are going to be 'commas', places in the text where you have to breathe. I see playing the flute in the same light. We don't have words, but there is a natural musical breath, which gives you obvious places to breathe within long phrases."
As far as breathing goes, Davies has an unexpected ally: a small trampoline. "A good morning's work will be three hours long, but there comes a point where lips start to tire, the breathing system needs help. Five minutes of going up and own on the trampoline replenishes the oxygen, opens up the cavities."
No doubt singers occasionally need to get mindless too, even when, like soprano Susan Bullock, they are about to undertake one of the most taxing roles in the repertoire, that of Isolde in Wagner's Tristan and Isolde. She has sung the role in German; at English National Opera later this month, she will sing it in English. But whichever the language, the learning process must be taken slowly: "Trying to learn something too quickly risks shocking your vocal apparatus. I start by reading the text as if it's a play; and if it's in a language other than English I translate every single word, even the scenes I'm not in, so that I know exactly what's going on. When it comes to learning the notes, you can memorise a role by sitting and looking at the score, but it won't be in your bones and muscles: you won't have the shapes, the colours of the words in your mouth. So I work with a pianist. I sight-read quite well, so I don't need to have the notes bashed into my brain: it's more about hearing the colours and harmonies underneath my voice. When I work with the pianist Phillip Thomas, he'll make a tape of my part so that I can sing along in my head, on a plane or anywhere. For running the words, that is really helpful. Then I begin to work with a coach, and the memorising starts."
What, then, of re-learning Isolde in English? "I only have to hear the opening chords and the German words come. So I decided to pretend that I'd never sung it before in my life, and went through the whole process again. It's a constant battle between two parts of the brain, one singing in German, one in English; but once I set foot on the Coliseum stage, where I've only ever sung in English, the German will fade into the background. But there are problems with translations. When Tristan and Isolde drink the love potion, for example, the German is 'Treuloser Holder!' The sound of 'Treuloser' gives you something to bite on, but in English it's 'faithless', which has nothing to dig into. Later, the translation has 'when bright with day's deceitful flame', but I don't like to sing 'day's' on a top G so I've changed it to 'when bright with lying daylight's flame', because for me 'lying' has a better vowel."
None of this implies any criticism of Andrew Porter's translation, which Bullock describes as "fantastic"; it is simply making the translation work for her, just as any performer will want to make the music their own.
At her Wigmore Hall performance, Philippa Davies will play, from memory, a piece that is already intensely personal: Aspects of a Landscape was written (though not for her) by her husband Paul Reade, who died in 1997. In such circumstances, the phrase "learning by heart" takes on new significance: "I've played the piece innumerable times, and I've learnt individual movements, but never the whole thing. Maybe I haven't trusted myself. But the learning process is the same for all pieces, and while certain technical things are still tricky, I feel strongly that it's my piece, and of course I want to play it better. I always feel that Paul is there, I know the atmosphere that he would want, and I have him in my head, giving a critical appraisal. That's helpful in getting to the point where I'm playing it by heart, which is to say playing it with feeling."
'Practice Session': BBC Radio 4, Tuesday; 'Tristan and Isolde': Coliseum, London WC2 (020 7632 8300) to 8 June; Philippa Davies: Wigmore Hall, London W1 (020 7935 2141) 10 JuneReuse content