sentences:  While the straight and level zero fret improves the tuning accuracy along the lower frets (from fret 1 to 3 mainly) the elevated fret keeps the string action higher and helps to avoid string buzz.The term "guitar intonation" denotes to what precision the ideal equally tempered musical scale can be produced by a guitar, while "piano intonation" refers to the setup procedure of the individual hammers in the piano keyboard.A conventional nut or an elevated zero fret will cause pitch errors on the lower frets due to the increased pressure on the strings.