In a section of music, the vocalists or musicians all sing or play the same note or notes that are an octave apart. This can be used to create harmony or contrast between voices or instruments. There are two types of sections: harmonic and melodic. In a harmonic section, all the parts sound the same note but in a melodic section, the notes played by different instruments or singers change throughout the piece. Harmonic sections are common in classical music and jazz. A famous example is John Coltrane's saxophone solo in "My Favorite Thing." Other instruments that can be used in a harmonic section include guitar, piano, and violin. Melodic sections can be used to great effect in pop music too. Think of the chorus in a song like "Happy Birthday" where everyone joins in at the end with a loud "happy birthday". That's because they're all singing the same note - B flat - but changing notes within a melody is what makes it interesting. A melody can be played on one instrument, such as a guitar, or spread out across several players. It can also be recorded directly to tape or digitally stored in a computer file.