Stretch tuning is a common method used to tune acoustic pianos. This unique method of tuning makes the upper-range notes slightly higher (sharper) in pitch and the lower-range notes slightly lower (flatter) in pitch. For this reason you might perceive certain individual pitches as being incorrect. However, this is the way many acoustic pians are tuned. The reason for this type of tuning is so that the overall piano will sound in tune, especially when playing certain common intervals and harmonies.
Roland digital pianos also use stretch tuning. However, on certain Roland digital pianos that include the Piano Designer feature, it is possible to change the tuning if desired..