As a musical instrument maker I have several tuning aids which have served me well over the years but I was looking for a device that would recognise more concisely certain notes that other tuners fail to be happy about. Also I wanted a tuner that would measure harmonic positions within a complex sound. This is at times a tall order but I think the Auto Strobe 490 is achieving this. My first tuner was a Yamaha PT4 which cost close to $1000 back in 1976.. it was very good but the Peterson Auto strobe is a great improvement... long may it last. I am a woodwind instrument maker but I also have other types of instruments to tune , Accordion type reeds and some stringed instruments. One feature of this type of tuner is the way it shows the decay of a note. The extreme accuracy may appear to be overkill for musical instrument work but there are times when measuring a pitch to one thousandth of a semitone is usefull.