tune
1. a melody, esp one for which harmony is not essential
2. the most important part in a musical texture
3. the condition of producing accurately pitched notes, intervals, etc. (esp in the phrases in tune, out of tune)
4. accurate correspondence of pitch and intonation between instruments (esp in the phrases in tune, out of tune)
5. the correct adjustment of a radio, television, or some other electronic circuit with respect to the required frequency (esp in the phrases in tune, out of tune)
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005