PTL is a new kind of music sequencer in his first stage of development. Limitation of Midi for contemporary music is well known. Nowadays, there is no sequencer dedicated to real time synthesis environment such as pure data from Miller Puckett or Max from IRCAM. PTL is an attempt to fill this lack. Unlike classical sequencers based on midi protocol, PTL permits any kind of message (number, text, array, etc…) to be sent (using different protocol like OSC, or FUDI) to a virtual instrument and to be graphically represented onto a time line with a symbol created by the user. With basic shapes like dots, segments and circles, the compositor can use his sensitivity to make a drawing of the score that expresses graphically the music he writes. For convenience, some of the shapes characteristics chosen by the user, like coordinates or colors, can become the virtual instrument parameters. By making the link between a graphical parameter and a musical one (like a Y coordinate translated into a frequency), we create a rule that gives a meaning to the graphical score. So, editing graphical symbols with the mouse will imply some musical changes.

We can define PTL as a graphical language; the user draws symbols and tells to the sequencer how to interpret them automatically as messages to be sent to a virtual instrument. PTL can fit as well for real time and non real time use.