"pentatonic is chinese"
---> pentatonic just means a five note scale. There are several pentatonic scales, many of which originated in China; however, the blues scale, which is a derivative of the minor pentatonic scale (derived from the standard European Aeolian mode), was developed in America.
"and I thought jazz originated in gypsy villages in Europe"
---> the jazz we are talking about is a musical style that evolved in America from American Blues music. The standard 12 bar blues was expanded upon and made more complicated, then chord-scale relationships came about, and jazz was born - a truly American musical style.
Blues | F7 | F7 | F7 | F7| Bb7 | Bb7 | F7 | F7 | C7 | Bb7 | F7 | C7 |
evolved into
Jazz | F7 | Bb7 | F7 | Cm7 - B7 | Bb7 | Bdim | F7/C - C#dim | Dm7 | Gm7 | Gb13 | F7 | C7 |
See how Blues and Jazz are related?
"You must stab him in the heart with the Bone Saber of Zumacalis... well, you could stab him in the head or the lungs, too... and the saber, it probably doesn't have to be bone, just anything sharp lying around the house... you could poke him with a pillow and kill him."
- Aqua Teen Hunger Force, The Universal Re-Monster