The present invention relates to a method for manufacturing a musical instrument, in which method a musical instrument is manufacturing for one or several parts and of which parts at least one part is manufactured of plastic material compound, which includes thermoplastic polymer. The elastomeric grommet, which is annular when unstressed, outlines a region on the fluid-impervious sheet. Improved protection of a switch from damage, by a reduction in heat-generation quantity in the switch, is one of the achieved advantages. The invention includes a locking device for locking the single drive mechanism in one of first and second modes of operation corresponding to tilting movement and telescoping movement. The mass spectrometer is instructed to perform a dependent scan for the ion at the second interval producing a spectrum for a background.