Python code to write a .pdf file of empty music staff for composing music. You can print it out and start writing.

MusicStaff.py

import fpdf

def makePage(w=297,h=210):
    '''Page width and height in mm.  Default is A4 landscape'''
    pdf = fpdf.FPDF(unit='mm', format=(w, h))
    pdf.add_page()
    return(pdf)

def drawLines(pdf, titlegap = 30, stafflinegap = 4, linegap = 10):
    '''All dimensions in mm.  5 lines for music notation.
Arbitarily chose to have linegap margins'''
    deltay = titlegap
    with pdf.new_path() as path:
        while deltay+5*stafflinegap+linegap<=pdf.h:
            for i in range(0,5):
                path.move_to(linegap, deltay)
                path.line_to(pdf.w-linegap, deltay)
                deltay = deltay + stafflinegap
            deltay = deltay + linegap
        print("Another line would start outside page margins at: "+str(deltay+5*stafflinegap+linegap))
        path.close()

if __name__ == "__main__":
    pdf = makePage(w=297,h=210)
    drawLines(pdf,titlegap=30, stafflinegap=4, linegap=10)
    pdf.output("SM_A4Landscape.pdf")

    pdf = makePage(w=210,h=297)
    drawLines(pdf,titlegap=50, stafflinegap=4, linegap=10)
    pdf.output("SM_A4Portrait.pdf")