With Linux

Generating a PDF file from any program under Linux needs to use a special printer driver that saves the graphic commands into a file instead of actually printing them on paper.

You can then either send this file by e-mail to somebody else, or process it with PDFtoMusic to convert it into the file format you need.

With KDE, the "kprinter" command (KDEPrint package) includes an option to generate a PDF file:

If this option is not included in your distribution, you'll probably need to use cups-pdf.
To install it under Ubuntu, please refer to this document:
http://ubuntu.wordpress.com/2006/03/23/print-to-pdf-using-cups-pdf/
To install it under another distribution, please read:
http://www.physik.uni-wuerzburg.de/~vrbehr/cups-pdf/download.shtml