The arpa jarocha is a harp from Veracruz, Mexico. It is one of the main instruments in a conjunto jarocho, a type of Mexican folk ensemble and is most associated with performing sones jarochos, a musical style that blends Spanish and African-influenced rhythms. The arpa is typically heard providing the main melodies, while instruments such as the jarana guitar and the requinto provide basic rhythms or counter-melodies.
The arpa jarocha was originally seen in Michaocàn, Jalisco, Southern Veracruz, and the highest part of the Chiapas where it was played by the Chamula Indians. Now it can be found in Mexico City, Tijuana, and Southern California. 
It is a wooden harp with 32-36 strings tuned diatonically over five octaves. The performer plays a bass line on the low strings with one hand and supplies arpeggiated melodies on the higher strings with the other hand. The top of the soundbox on this instrument arches outward, due to the tension of the strings. Unlike other Mexican harps, the arpa jarocha has its sound holes located on the back of the sound box instead of on the front. In Michoacàn, the harps have a large sound box and while one player plucks the strings, another player will use the sound board like a drum. The Chamula Indians' harp was much smaller with a wide section of mid-range strings missing; most harps have bass strings and high strings, so this particular harp would have many of the middle stings absent.
^ abcCourteau, Mona-Lyn and Daniel Sheehy (2003). "Part III Musical Instruments: 13. Stringed Instruments: Harp.". In John Shepherd, et al. Continuum Encyclopedia Of Popular Music Of The World. Vol. 2. Bloomsbury Academic. pp. 427–437. ISBN9780826463227.