Xen concepts for beginners: Difference between revisions

Inthar (talk | contribs)
Inthar (talk | contribs)
Line 56: Line 56:
Every MOS scale with m large steps and n small steps is a mode of some pattern. This is why you only need to write mL ns for an octave-equivalent MOS scale. For example, every 5L3s MOS scale is a mode of the pattern LLsLLsLs.
Every MOS scale with m large steps and n small steps is a mode of some pattern. This is why you only need to write mL ns for an octave-equivalent MOS scale. For example, every 5L3s MOS scale is a mode of the pattern LLsLLsLs.


An important way that MOS scales vary is [[hardness]], the ratio of the size of the L step to the size of the s step. Hardness can range from 1 to infinity. The larger the hardness, the harder the MOS tuning; the smaller (closer to 1) the hardness, the softer the tuning. The two extremes are where the MOS pattern no longer holds; 1 is where L and s steps are equal, and infinity is where s is so small that it disappears.
An important way that MOS scales vary is [[hardness]], defined as the size (in cents) of the L divided by the size (in cents) of the s step. Hardness can range from 1 to infinity. The larger the hardness, the harder the MOS tuning; the smaller (closer to 1) the hardness, the softer the tuning. The two extremes are where the MOS pattern no longer holds; 1 is where L and s steps are equal, and infinity is where s is so small that it disappears.


Any given MOS pattern is available in more than one edo, and the basic tuning of a MOS pattern gives the smallest edo that provides that MOS pattern. To adjust the hardness of a MOS provided by an edo, we can add two edos, obtaining an edo where the hardness is the mediant of the two original edos'. For a diatonic example, 12edo has basic (L/s = 2/1) diatonic, 17edo has hard (L/s = 3/1) diatonic, and 19edo has soft (L/s = 3/2) diatonic.  
Any given MOS pattern is available in more than one edo, and the basic tuning of a MOS pattern gives the smallest edo that provides that MOS pattern. To adjust the hardness of a MOS provided by an edo, we can add two edos, obtaining an edo where the hardness is the mediant of the two original edos'. For a diatonic example, 12edo has basic (L/s = 2/1) diatonic, 17edo has hard (L/s = 3/1) diatonic, and 19edo has soft (L/s = 3/2) diatonic.