Few would argue that a complete cycle of Bach’s church cantatas is just about the most ambitious recording project anyone could undertake. Masaaki Suzuki, director of the Bach Collegium Japan and the latest man to pull off the monumental task, seems remarkably relaxed about it when I talk to him the morning after the very last notes have sounded. Perhaps it is because it has been achieved almost by stealth. ‘At the beginning we hadn’t thought of doing the cantatas complete,’ he tells me. ‘I’d been performing them since I came back from my studies in the Netherlands in 1983. They were part of my life already, and the only idea I had in 1995 was of making some sort of record of our activities. But from the start BIS issued the CDs with volume numbers. I didn’t realise then how far we would go, and I certainly didn’t count how many years or how many CDs it would take!’

It can now be confirmed that it has taken 18 years and 55 CDs – a shorter time than Harnoncourt and Leonhardt took over their pioneering cycle (21 years), but longer than Koopman (10 years) and Gardiner (recorded on his Bach Pilgrimage in 2000 but not all finally issued until earlier this year). What is more, it seems to have been accomplished without evident sign of the emotional or financial trauma some of those other cycles endured. No doubt the personality of Suzuki himself has got something to do with that. Gentle, kindly of face and quick to laugh in a friendly manner, he seems unaffected by ego, while at the same time clear of what he wants and what the music means to him. At sessions he works quickly and patiently in an atmosphere of effectively led collaboration (he himself maintains that ‘basically we are doing chamber music’), and when the producer’s voice declares the final take of Cantata No 191 a success and the musicians politely applaud each other, they seem to be celebrating Bach’s music as much as their own achievement. ‘It’s very good that we have completed it,’ Suzuki says, ‘but it’s a pity that people will now think that’s the end of it all. I really want to carry on with this music. People need to rediscover it as part of their daily lives and part of worship.’

Suzuki has never hidden the fact that his own quiet Christian faith provides a solid background to his artistic life, and perhaps nowhere is belief more of a help to understanding than in these cantatas, written for Lutheran Sunday services and tied as they are to the contours of the church year. As BIS’s founder and owner Robert von Bahr remarks, ‘These cantatas expressed Bach’s belief in God, and I’ve never heard anyone express that like Masaaki. This cycle is his personal communion with God.’ Over the years Suzuki has developed a habit at rehearsals of explaining to all his musicians – singers and players – the meaning of the text and something of its liturgical background. ‘It makes it easier for them to get into the right mood. It’s not always easy for us in Japan to understand why a certain parable might be associated with one Sunday and not the next. For instance, for the Japanese it’s very clear what Christmas is: it’s when we have a party, so that’s fine! But straight after it, on December 26, all the shops and department stores change their decor for the New Year, which to the Japanese is a much more important feast. So every time we do Christmas cantatas or the Christmas Oratorio I have to explain that this is actually the start of the liturgical period leading up to Passiontide and Easter. In concerts I often like to try and put Christmas and Passion (or Easter) music together.’

Suzuki is telling me this in a conference room in a quiet corner of the Shoin Women’s University in his home town of Kobe, where he once taught and in whose chapel all the Bach recordings were made. Musically, Suzuki is certain that (bar a few details) the approach to interpretation has changed little since the earliest days. Perhaps the most noticeable development is that whereas many of the soloists in the early volumes were Japanese, Suzuki has increasingly turned to Europe for his soloists. True, bass Peter Kooij was there right from the beginning, and tenor Gerd Türk from Volume 2, but fine singers such as Midori Suzuki, Yoshikazu Mera and Makoto Sakurada have gradually given way to the likes of Carolyn Sampson, Joanne Lunn, Robin Blaze, Kai Wessel and Roderick Williams. ‘We did have those three or four really good Japanese singers,’ says Suzuki, ‘but generally this kind of repertory is not as familiar for the Japanese as, say, opera, because of course there is no tradition here of Christian sacred music.’ Kooij and Türk, both of whom are on this last recording, have become good friends, and Suzuki also confesses that he often gets on better with European and American singers. ‘Somehow I personally find it easier to communicate with someone who is more open than Japanese people usually are!’

Right from the start, Suzuki has enjoyed the participation of members of his family in his recordings. His wife, Tamaki, is an alto in the choir (and is also involved in the group’s management), his brother Hidemi is the continuo cellist, and more recently his son, Masato, has joined as harpsichordist. ‘To work with your brother and your son is not always easy,’ says Suzuki with a smile. ‘We’ve had some arguments, but if we sometimes have different opinions and different ways of expressing them, we are at least basically similar in our ideas. What’s interesting is that Masato in many other ways is very different now. He has grown up in the harpsichord and continuo atmosphere, but he’s also interested in composing, he’s working as a stage director, and he likes to make DVDs. He’s from a completely different generation. And I don’t think his generation could do Bach in the same way we’ve been doing it; they have a completely different perception of how to enjoy the project. Some of them have the same feeling for Bach as they do for rock music or new music and so on. It’s all the same for that generation, and that’s fascinating.’

Another important presence, of course, has been von Bahr, who actually produced the first volumes. He is here in Kobe, too, to witness the last leg of the project he himself hatched, and with a shudder he recalls the ‘eerie’ atmosphere he encountered at the first recording, which took place in 1995 only weeks after Kobe had been hit by an earthquake that claimed more than 4000 lives and devastated much of the lower-lying part of the city. At a press conference the day before our interview, however, he and Suzuki had joked about the long ‘discussions’ (a euphemism, one suspects, for ‘disputes’) they had had about how certain things should be done. ‘On Vol 1, the Sinfonia of Cantata No 196 is only about two minutes long, but it took us two hours to record!’ Suzuki laughs. ‘There’s one note in the score where it’s not clear if it’s an F or an F sharp, and it led to a long “discussion’’ about all sorts of things! But it was good to get these things cleared up early on, and it enabled us to get closer to each other. Now, “F or F sharp?” has become for us a kind of symbolic expression of that!’

It is certain that von Bahr played a major part in establishing the Bach Collegium’s worldwide reputation as Bach interpreters. Yet he explains to me how when Suzuki first sent him a cassette of the group for consideration it had no Bach on it. ‘Actually, I mainly liked the cornett playing! Then they invited me to come to Japan to hear them in Bach. I’d made the same assumption as everyone else – Japanese artists playing Bach? But straight away I was bowled over and formed the idea to record the cantatas. I had a big job persuading people, and I had to travel around the world twice to promote it. No other project ever meant more to me.’

If hearing Japanese artists performing Bach with such understanding and sympathy was a surprise for many, it is fair to say that there was something extraordinarily moving about it, too. Suzuki himself studied in Europe (harpsichord with Ton Koopman, organ with Piet Kee), as did many other members of his group including his brother and the leader, Ryo Terakado; Suzuki has no doubt that there is a fruitful meeting of cultures at work here. ‘The Japanese mentality understands the merits of homogeneity. In the Bach Collegium we have three or four singers per part and it’s easy to get a homogeneous sound because they’re always thinking in terms of working together for the same end. In the orchestra, too, where the older players who have studied in Europe know the kind of sound they want to make, the younger ones can adapt their playing to sound well with that. I never find it so easy to achieve that when I work with European or American ensembles. On the other hand we have sometimes been criticised for being a little too passive, and it’s true that if you pursue this homogeneity too much you lose some of the drama. So for me the task is always to find a good balance. Sometimes I incline towards this homogeneous sound and at others I have to kick the musicians somehow into being spontaneous. Actually, did you know the word “spontaneous” doesn’t exist in Japanese? At least, it’s not taught in schools; there it’s always “discipline”!’

One question any conductor of Bach’s cantatas has come (no doubt wearily) to expect is what his or her attitude is to the ‘one to a part’ issue. It is more than 30 years since Joshua Rifkin first put forward his theory that the forces Bach had at his command at the Thomaskirche in Leipzig meant that his cantatas were performed with one voice on each part, those voices singing the solos as well as the ‘choral’ numbers. One to a part is already more common now than it was when Suzuki began his cycle using a choir with four voices per part, a size he has stuck with in essence ever since; so I wonder what he feels about it now. ‘What Rifkin says is very interesting – his research is very precise and very accurate,’ says Suzuki. ‘But I think the numbers of singers and players you use should depend on the personality of the musicians themselves. There are certainly many Bach cantatas that work very well with one person per part, and I have sometimes performed them like that in concert, but you have to have very, very good singers and appropriate music. So one has to be flexible, and in fact I don’t commit myself to this argument at all. I don’t really care how many singers there are. The only thing I can’t understand is why Rifkin performs the B minor Mass with one to a part; for me it’s a pity, because musically it doesn’t work and anyway there’s no evidence of how Bach himself might have performed the B minor Mass.’

As the time comes to wind up the interview, I ask the question that I always have for anyone who has completed a major cycle such as this: which cantatas still surprise you? ‘Oh, there are so many,’ he replies straight away. ‘Let’s see – No 1, No 2, No 3, No 4...’