Tonometric meaurements for 12 Nasca panpipes, two of which can be dated, are presented. The acoustical properties of the two types of identified pipes differ significantly. Specific frequencies reoccur among different instruments. This allowed building of a sequence of steps which are based on equal frequency intervals in hertz, rather than on a logarithmic series. The accuracy of tuning was better than 10 Hz for over 60% of the pipes. This is adequate for panpipes that are activated by mouth blowing.