This is what we found on Wikipedia regarding the Ay Em:

Southern hip hop, also known as Southern rap, South Coast hip hop, or dirty south, is a blanket term for a regional genre of American hip hop music that emerged in the Southern United States, especially in Georgia, Texas, Louisiana, Tennessee, and Florida—often titled “The Big 5,” five states which constitute the "Southern Network" in rap music.

The music was a reaction to the 1980s flow of hip hop culture from New York City and the Los Angeles area and can be considered the third major American hip hop scene, alongside East Coast hip hop and West Coast hip hop. Many early Southern rap artists released their music independently or on mixtapes after encountering difficulty securing record-label contracts in the 1990s. By the early 2000s, many Southern artists had attained success, and as the decade went on, both mainstream and underground varieties of Southern hip hop became among the most popular and influential of the entire genre.