Norton Commander (motorcycle) Norton Commander (motorcycle) The Commander was a Norton motorcycle with a Wankel rotary engine. The first Norton Wankel motorcycle was the 1987 air-cooled Classic, built as a special edition of just 100 machines. It was followed by the air-cooled Interpol 2 model. The Commander was a liquid-cooled successor to the Interpol 2, liquid cooling being adopted for greater power and reliability. The Commander's final-drive chain was protected by a full enclosure. Some cycle parts (such as front wheel, forks & brakes) were bought-in Yamaha items. Two types of Commander were built. The P52 was a single-seat model equipped for police
Augmented-fourths tuning lefty-righty symmetry. These properties characterize augmented-fourths tunings among non-trivial tunings. The set of augmented-fourths tunings has three properties that simplify learning by beginners and improvisation by experts: Regular intervals, string repetition, and lefty-righty symmetry. Besides the set of augmented-fourths tuning, exactly one other set of tunings has these three properties—the "trivial" class of one-note tunings, which contains the C-C-C-C-C-C tuning, for example. Augmented-fourths tunings have extended range. Because each of its tritone-intervals between successive strings is wider than the perfect-fourth intervals (and one major third) of standard tuning, augmented-fourths tunings have greater range than standard tuning—six additional notes, only one