MNS Recordings
Most Music Notation Software (MNS) programs allow you to export your music to an MP3. The only catch is that there are no voices. Just instruments and/or vocal note sounds (depending on how you have set up your music). This is the most basic a easy way to create a recording and it really does give your customers a glimpse as to what your music would sound like. It is also free and fairly simple to set up.
Here is a great tutorial on how to export Finale and Sibelius files to MP3: Finale & Sibelius Export to MP3.
Here is a great tutorial on how to export Finale and Sibelius files to MP3: Finale & Sibelius Export to MP3.