Melodic segmentation is an important topic for music information retrieval, because it divides melodies into musically relevant units. Most influential theories on melodic segmentation of the last decades have stressed the role of pitch for melodic segmentation. The general assumption was, that relatively large changes or distances in any musical parameter like pitch, time, dynamics, or melodic movement mark segment boundaries. This has generally been accepted despite the lack of empirical studies. Here an empirical study is presented, that investigates the influence of inter-onset-intervals (IOI), intensity accents, pitch intervals, and pitch interval direction changes. The results show a significant influence only for IOIs and intensity, but neither for pitch intervals nor for changes in interval direction. The validity of the results and possible explanations are discussed and directions of further investigations are outlined.