What is On2 Salsa
Son is danced on “contra tiempo”, which in counts, is danced on 234 678. Dancing on contra tiempo is often reffered to as connecting with the rythm of the music rather then the singing and by that, connecting to the 2/3 son clave which accentuate 23 5 6.5 8, the Base which accentuate 3.5 4 6.5 8, as well as the congas (which is not a original instrument in son) which accentuates 2 4 4.5 6 8.
The term On2 Salsa includes a number of salsa styles. What combines them is the timing of the “break step” which is made on the 2nd and 6th count in the music.
Popular styles that uses this timing are NY-style, Puertorican style, classic Mambo, Palladium style mambo, Power on2.
These styles all have their origin in the elegant Cuban dance, Son. Son is danced on “contra tiempo” which also has its break step on 2.
Palladium style
The developmement of the Mambo music had been happening already in the 1930s but it was at the Palladium, also Known as “the home of the mambo,” the Palladium was where Mambo gained it’s fame and popularity. The Palladium was New York's most popular venue for Latin dance music from from late 1940. By the early 1950s it became an international dance craze. The dance was based on the Cuban son, but with with the addition of turns borrowed from American swing dancing, and solo dance steps adopted from Cuban rumba, Puerto Rican bomba, and African American jazz.
Cha cha cha
Another dance that has a break step on2 is the Cuban dance cha-cha-cha (also called cha-cha). It is danced to the music of the same name introduced by the Cuban composer and violinist Enrique Jorrin in the early 1950s. This rhythm was developed from the danzón-mambo. Jorrín noticed that many of the dancers at these gigs had difficulty with the syncopated rhythms of the danzón-mambo. To make his music more appealing to dancers, Jorrín began composing songs where the melody was marked strongly on the first downbeat and the rhythm was less syncopated. The basic footwork pattern of cha-cha-cha (one, two, three, cha-cha-one, two, three)
NY- Style Salsa
Often referred to as Modern Mambo, NY-style is the most common On2 style internationally. Although the style of dancing already was popular in the NY salsa scen, one teacher rose above all with a system that was clear and easy to understand. Eddie Torres was that person. He was one of the first teachers to formalise salsa with counts of the music. Much like the chahcacha NY-style uses the first beat downbeat of the music and then break on the 2nd. This makes the style much easier for on1 dancers to learn since they keep stepping on the same beats and only need to get used to breaking the step on2 instead of on1.
Puerto Rican-Style Salsa
Here is a great video with Rodrigo Cortazar where he demonstrates the different ways of dancing On2.