The Mostly Modern Festival, which opens at the Bank of Ireland Arts Centre tomorrow afternoon, is an extension of the Mostly Modern series. This has become a key provider of new music in Dublin in recent years, and the focus of the festival's music will be, well, newer than anything you can hear anywhere else. The festival sees the debut of the Barry Guy (right) New Orchestra, bringing together, from around the world, a group leading players in the area of improvised music. The orchestra can be heard on Wednesday evening in the premiere of Guy's Inscape, and anyone wanting to understand its inner workings can attend open rehearsals each afternoon from Sunday to Tuesday. The Sunday to Tuesday concerts feature various of its members - among them Evan Parker and Mats Gustafsson (saxophones), Marilyn Crispell (piano), Paul Lytton and Raymond Strid (percussion) and Barry Guy himself (on double bass). Also in the festival's concert line-up is a lunchtime programme on Thursday when recorder player Peter Wells gives the premiere of a new work by Siobhan Cleary in a programme that includes prize-winning pieces from Mostly Modern's Irish and international competitions.