2. We can purposely shift certain scale notes closer to or farther from their neighbors to make perfect intervals or chords in some places. If we choose wisely, we can make the most important chords in a given key be the perfect ones. This is the concept behind Just Intonation (JST in the VS-1 temperament menu). In the key of C, the chords of C major, F Major, and G Major can each have perfectly harmonious tuning intervals within. Unfortunately, the price to pay is that other chords, especially those in more remote keys like C# and F#, sound much worse than they would in equal temperament. If an instrument like a piano is tuned in Just Major temperament for the key of C, notes and chords that fall in the C Major scale sound wonderful. Modulating to the key of G, most chords sound good, some not quite as good. If one takes a more adventurous trek into the key of E, say, some real "ear-sores" start to develop in certain chords and intervals. Historically, the clinkers are dubbed "wolf tones" which gives some indication of their "charm".
3. Between the extremes given above, there are countless compromises. Why not settle for some "nearly perfect" chords in the most popular key signatures, while keeping the "wolves" at bay in the less traveled ones? There are about as many such "well tempered" scales as there have been minds conceiving of them. Each such temperament generally takes the name of its earliest inventor or biggest proponent. Some of the more successful ones, like Werkmeister (WRK), Young (YNG), Kirnberger (KRN), and Kellner (KLN) are included in current models of peterson tuners. Besides stock historic temperaments, Peterson Virtual Strobe Tuners also feature unique instrument specific temperaments such as GTR for guitar, BAS for bass, and (VS-II/V-SAM only) E9 & C6 tempered tuning for pedal steel guitar. The VS-S StroboStomp pedal tuner/DI also features four optimized Buzz Feiten Tuning System presets for electric guitar, acoustic guitar, bass guitar and 12-string guitar. All Peterson Tuners (except the VS-1) are user programmable allowing the saving of from two to 244 user teperaments to memory. The V-SAM allows you to adjust any temperament to any one of 12 roots making these temperaments available in any specific key.