The easiest part of running a new music group in Britain is probably the beginning. You gather some like-minded musicians, make a programme, find a venue and perform. After that it gets harder: establishing a reputation, persuading someone to fund you, negotiating with promoters, maintaining the commitment of your musicians, keeping going year after year. But EXAUDI have done much more than just keep going: they have established new standards for what an ensemble of solo voices can achieve and championed a host of spectacularly ambitious, beautiful, challenging works, both their own commissions and revivals of music waiting for a group of this quality to come along. Their fifteenth birthday is, then, something to celebrate, and the Wigmore Hall an ideal venue in which to celebrate a consort of beautifully blended voices.