The word "harp" comes from the greek word "arpo", meaning to snatch or grasp. Various types of harps are found in Africa, Europe, both North and South America, and Asia. In antiquity, harps and the closely related lyres were very prominent in all early cultures. It was a very popular instrument with medieval bards, troubadours, and minnesingers throughout the Spanish empire. Harps continued to grow in popularity through improvement in their design and construction through the beginning of the 20th century.
The harp found its early orchestral use in concerti by many baroque and classical composers (Handel, J. C. Bach, Mozart). It later found its way to the London opera houses, where it flourished. From there it skyrocketed in pretty much every genre of music. It is popular in rock, jazz, classical, orchestral, opera, metal, and experimental. It is also strongly used in most church music. In christianity, the harp is associated with the etherial and heaven. Many christian paintings and drawings have angels playing the harp.
It was nice getting back to a topic that actually has information published about it! To celebrate, here is TWO wonderful harp filled videos: Laser Harp Fully Functional and Beastly harpist playing free bird! And because I feel like it, here are some photos: