Time Structured Mapping (TSM) is a score based system created and used by the composer Pete M Wyer. It uses the bar-lines found in conventional musical scores to indicate durational periods during which performers, who may include actors, singers, dancers, poets as well as musicians, are given instructions, which may include conventional musical scoring or improvisational guidelines. The system allows large and sometimes disparate groups to improvise together coherently, or to combine improvisation with scored music or with other media. It has been used to get orchestras, including the Orchestra of the Swan (see below), to improvise effectively and in educational projects, to combine student musicians with professionals, such as with Welsh National Opera and to combine other media such as dance and poetry with musical improvisation in a structured form, such as with Miro Dance Theatre, Philadelphia. The flexibility of the system has allowed for the combination of musicians from very different backgrounds, as well as disparate ensembles with players of very different standards. Works generally combine improvisation with conventional scoring and move frequently from one system to the other. The synchronisation using 'clock-time' as a basis has also enabled works made up of players who are spatially separated such as with Four Bridges which was performed simultaneously in Britain, Germany, America and India, it allows for works which alter the conventional relationship of the composer with the musician by involving the performer directly into the creative process. Beginnings - The Simultaneity Project In 2004 Wyer began creating Simultaneity works: works that made recordings at the same time in different locations. The first recordings took place around Columbus Circle, New York – Wyer mapped out a circumference that passed through the Time Warner building and around the periphery of Columbus Circle itself and, with the help of a team of volunteer staff from WNYC radio, made a series of simultaneous recordings that, when played back across multiple speakers, gave what he described as a ‘God’s ear view’ of the location – the experience of being at all points simultaneously; cars, subway trains and people moved from speaker to speaker, featuring the endless rotation of revolving doors that interfaced the very contrasting sonic landscape of the interior of the Time Warner Building with the bustling Manhattan streets outside. This led to Simultaneity recordings that were not made in the same location: in December 2004, with volunteers primarily from CEC Canada's