Hello, I have interesting task. I want to build a picture of a guitar chord using metapost. For now, I only knew how to make a chord grid: \startreusableMPgraphic{chordgrid} drawoptions(withpen pencircle scaled 0.4pt withcolor black) ; draw hlingrid(0, 5, 1, 0.8cm, 1cm) ; draw vlingrid(0, 4, 1, 1cm, 0.8cm) ; \stopreusableMPgraphic \define[0]\ChGrid{\dontleavehmode\useMPgraphic{chordgrid}\hskip2mm} \starttext \ChGrid \stoptext I need to change it so that I could specify fret numbers, i.e. six numbers for each string, and draw a filled circles in these positions. I've started with a command like this \define[6]\Ch{\dontleavehmode\useMPgraphic{chordgrid}... I'm not sure what to do next... How to pass these parameters into MP, how to organize the loop... For a test, \Ch[1][3][1][2][1][1] should produce |-O-|---|---|---| |-O-|---|---|---| |---|-O-|---|---| |-O-|---|---|---| |---|---|-O-|---| |-O-|---|---|---| Please, help me with it. -- Best Regards, Vyatcheslav Yatskovsky