I have spent the last few days in Wrocław in Poland. A beautiful city, with lots going on. They are currently building a new home for the Philharmonic (which I am told will be the best acoustic of any concert hall in central Europe) and the Euro 2012 football trophy has been unveiled since we have been here. There is lots happening. Also, yesterday it was 25°C, which was an added bonus.

We are here to record music by Grzegorz Gerwazy Gorczycki (1665 - 1734). His "Completorium" is stunning. We have one voice per part (OVPP), even in the strings - and it is such a pleasure to be here and to be around such incredibly talented and modest musicians. The singers, in particular, are exceptional.

It feels like a very small group to me, but with these smaller forces it feels like we have greater agility. Usually when trumpets are involved in such projects there are larger forces involved, so it is a real treat to play the natural trumpet in a more intimate environment. The instrument designation at the top of the part and in the score clearly says 'clarino' (from the latin word clarus). It is not a designation of instrument really (although it does tell us that it is a trumpet part in the higher register), it is more a performance direction to tell us to play delicately.

In fact, one person commented that when they saw that it would be OVPP and that there were two trumpets on the schedule for this recording that they thought the trumpets would be too loud and that we might dominate the texture - but they said that the balance has been beautiful and thanked us for playing sensitively - a real compliment from such a great colleague.

The 'clarino' trumpet parts are understated and incredibly beautiful. They are used in much the same way as the Cornetto was during the Renaissance period - for doubling voices, for providing a different instrumental colour for the ritornello themes and to symbolise the glory of heaven.

If you were to have a cursory glance at our trumpet parts in isolation, you may be forgiven for thinking that they would be easy to play. However easy they may look, playing them 100% perfectly - as they deserve to be played - takes a lot of energy, concentration and precision. Playing fairly quietly and still making a full sound that is rich in overtones is where the art of playing this kind of music lies. This kind of music requires you to have a good musical 'radar' (awareness of others):

• Firstly, you must know when you are playing with the singers - and of course to make your musical shape fit with the shape of the words (Anyway, I would go so far as to say to do this even when there aren't any words). You must also be at a suitable dynamic level so as to support their vowels but not to obscure their consonants within the musical texture.

• Secondly, you must know when to play the trumpet as an instrument in its own right - for the ritornello and antiphonal interjections. I sort-of imagine that there are still words happening. Generally, as we do not have the ritornello theme first (or the first fugue entries) this also requires that we emulate the other players' articulation: translating what we see from bow strokes and what we hear from their amazing singing and playing into the equivalent sounds on the trumpet.

We are using a historical, modified mean tone on the organ - which is absolute bliss for this kind of music - as it fits with the natural tuning of the harmonic series - the built-in tuning that nature intended. The mean tone has been modified as the work uses D major (in the movements with trumpets), but also E major in some of the other ones. Presumably the G# is where the natural meantone tuning anomaly would normally be 'hidden', but as this work uses E major, and the singers are singing in pure intervals (just intonation), I think it is concealed on the A# instead, so that we still have a nice low (compared to Equal Temperament) third (G#) in E major.

It is so fantastic to be involved in this project, with such incredible players and singers from all over the world and such clear and inspirational direction from the front.