((1)) Patch Work is a lisp-based visual programming environmentfor music. Propositions are made in this paper for the extension of Patch Work visual scheme to full object-oriented programming.((2)) The PatchWork (Laurson, Duthen, ICMC 1990; Malt, 1993) experience at IRCAM has proven thegreat interest shown by composers in visual programming. PatchWork has beendistributed, through the IRCAM user's group, to over a hundred musicians andresearchers in musicology. Many specialized libraries have been written atIRCAM and elsewhere adressing a wide variety of problems including newmodels for rhythm quantification (Assayag & al, ICMC 1994), or musicalconstraints propagation schemes (Rueda & al, ICMC 1993). Composers that didnot know a word in computer science have realized in PatchWork visualprograms (patches) of an amazing complexity, due to PatchWork originalmixture of functional programming and graphical data editing.Thus we have reached the point where we must ask ourselves : what is the threshold ofcomplexity, that is, when does the musician come and tell us : you guys have tocode in Lisp a new box doing this and that and modelling this musical datastructure, because it is beyond reachability by the mean of visual programming --and how can that threshold be pushed back ?