I offer traditional piano tuning by ear, with a tuning fork as a reference for the starting note A. In my first period of training of three years full-time my fellow students and I spent three or four hours every day in a small booth training our ears and hands to learn our craft. There is no shortcut for this training.
I always if possible, tune to concert pitch A440Hz. Usually I can raise your piano to concert pitch if it has slipped due to lack of tuning. This may take two or three tunings which can usually be done in one session. Rule of thumb is ¼ tone flat = 2 x tunings, 1 semitone flat =3 x tunings.
What is concert pitch?
Concert pitch is the agreed hertz frequency of musical instruments so that different instruments playing the same note (e.g. middle C) will make the same sound. If your piano has not been tuned or has been poorly tuned it will probably be at a different pitch to other instruments necessitating their re-tuning. The piano is designed to be tensioned to A440hz. Its tone as well as tuning will suffer if not kept at pitch.
Tuning by ear vs. electronic tuners.
To the listener, the usual perception is that the piano tuned by ear by an experienced tuner sounds better, more musical than the piano tuned with the help of an electronic aid. How can this be, surely the digital tuner must be accurate? They are but pianos are not, they are inherently flawed. Each note producing complex and compromised harmonics, the very characteristics that make the piano sound rich & beautiful. Every piano must be tuned individually to take account of its size, string length, the condition of the strings, the room and any requests of the pianist.
The 'traditional’ tuner usually stretches or sharpens the octaves in the treble to align the harmonic series of each pair of notes. In the bass the lower notes are flattened to achieve the same result. This can only be done by ear. The general perception of the tunings assisted by generic electronic tuning aids is that the treble sounds flat and the bass sharp.
The newest tuning software is superbly accurate assuming that the equipment has been programmed for every single piano it encounters, with all the string lengths and diameters. One size does not fit all.
I am not anti-technology, it advances at great pace and in time all these issues will be resolved at which point I’ll be happy to buy in and give my ears a well-earned rest but that time has not come yet.