But 'hit' is probably an overstatement. Hits are not the normal process of the lieder world. Holzmair's arrival has been cultivated by word of mouth: fed by a handful of obscure recordings and endorsed by the management (and audience) of the Wigmore Hall in London, where he has been recruited into the hall's unofficial family of favoured artists.
Critics compare his musical intelligence to that of Dietrich Fischer-Dieskau, the retiring laureate of native lieder voices. And like Fischer-Dieskau, he has a parallel stage career which, after a traditional apprenticeship among the second division theatres of German opera, recently broke through to division one, at the Vienna Staatsoper. With engagements pending at La Fenice, Salzburg and Covent Garden (Papageno in the new Magic Flute that opens later this year), it's clear that Holzmair stands on the threshold of serious international stardom.
The only thing that remains unclear is why it has taken so long - because Holzmair is 40, an advanced age to be on the threshold of anything. The answer is that he was a late starter. As a child, brought up near Linz in northern Austria, he sang with a well-known boys' choir and had, as he describes it, 'a high soprano voice that could do Queen of the Night with no difficulty' - which must have been worth hearing. But under pressure from his father, a businessman, he studied economics and took a job in commerce.
It wasn't until he was 27 that he went back to singing seriously; and then he did it cautiously, knowing his limitations. 'I am a high baritone, so there aren't that many opera roles I can sing comfortably: Pelleas, Papageno, the Barber, yes. Scarpia, no. And then I was worried that my voice wasn't big enough. But I found out that size is not the issue: it's how the voice carries. So I thought that maybe I could survive with what I had.'
For the next few years it was a matter of survival, with house baritone jobs in Berne and Gelsenkirchen and local one-night stands. But it was a chance to learn repertory, win competitions (including the important Vienna Musikverein lieder prize), and immerse himself in Schubert and Mahler, his greatest loves. In 1989 he was invited to give a lieder recital at the Wigmore Hall. The reviews were (no exaggeration) ecstatic; and on the basis of them, the Wigmore's management took the unprecedented step of asking him back three times the following year, with similar results.
Not only beautiful of tone and stylish, Holzmair lived his texts with an extraordinary ear for detail. Recital singing is, after all, a microscopic art, exposed to knowing audiences who listen for minutiae. It's more precise than opera; and the knowingness exerts an added strain on singers - although Holzmair says it can also be helpful: 'It means you can start on a different level of interpretation. But the important thing is not to let the demand for detail lure you into artifice. When you rehearse, yes, think about it word by word. But when you do the concert, no. Sophisticated singers are admirable but they don't touch your heart. Only natural singers do that. Singers who understand that there is no emotion so direct, so honest and so pure as in a German lied.'
To anyone who thinks of lieder as a cerebral, recherche corner of vocal repertory, this may be hard to accept. But the romantic verse on which most lieder rely is usually simplistic, anti-intellectual, and dependent on a finite catalogue of images. Once you know the German for love, loneliness and longing, and can ally these concepts to such natural phenomena as springtime, rushing brooks and wind in tree-tops, you've mastered the essential vocabulary. This emotional innocence can present problems to younger German singers (not to mention younger German audiences) who find them disconcertingly nave.
'But the truth,' says Holzmair, 'is that Schubert is simple, not nave. Three days ago I was walking in the Vienna Prater. It was spring, the constant theme of Romantic poetry; and I wondered, how can people in towns and cities feel the significance of the seasons changing? They don't know about the wind in tree-tops and little brooks coming out of rocks. These things have largely gone from their lives. And so has silence. In all the lieder, stille (silence) is, after liebe (love), the highest quality. But where is stille now - in the department store, the rail station, the airport? If nothing else, I hope I can give someone who comes to my recital for one and a half hours the chance to feel the silence of these songs.'
On cue, the phone rings. We are, after all, in an Italian hotel with Holzmair's agent, accompanist (the Schubert specialist Imogen Cooper), various concert staff, and an accommodation crisis that seems to require Signori White and Holzmair (at least) to share the same room, and bed, that night. I haven't as yet passed this information on. 'Don't worry,' Holzmair smiles with a seraphic otherworldliness. 'I never answer phones on a performance day.'
Wolfgang Holzmair and Imogen Cooper perform Schubert's 'Schwanengesang' at the Wigmore Hall, London W1, on Tuesday (071- 935 2141).