J Mascis is an American musician, best known as the lead singer and guitarist of the alternative rock band Dinosaur Jr.. Born on December 10, 1965, in Amherst, Massachusetts, he is recognized for his distinctive guitar style and powerful vocals, which have influenced many musicians in the indie rock scene. In addition to his work with Dinosaur Jr., Mascis has released solo albums and collaborated with various artists. He is also known for his contributions to the grunge movement in the late 1980s and early 1990s, helping to shape the sound of that era with his innovative approach to guitar playing.