Best License-Free Sound Libraries for Producers by Digital Sound Factory They focus on classic E-MU sound modules, which were popular in the 1980s and 1990s music world. Many hit songs used these original sounds, and Digital Sound Factory brings that same feeling into modern production. https://www.murfreesborovoice.com/article/130868/best-license-free-sound-libraries-for-producers-by-digital-sound-factory