With the rapid development of information communication technology, social media has become a necessary part of people's daily life. Recently, many music teachers have applied social media to augment their classes and enhance their teaching. This article explores the use of social media for musical instrument education, with a focus on the violin and piano. A qualitative semi-structured interview was conducted with eight music teachers from music centers and studios. Our participants revealed that social media creates a virtual environment to extend (but not to replace) face-to-face instruction, which facilities knowledge sharing, arouses students' interest, and supports communication. For pedagogy, social media helps students improve musical instrument playing techniques (e.g., posture, fingering, and rhythm) and musical styles. Drawbacks of applying social media are mainly the quality of content, difficulties in differentiating subtle differences (e.g., intonation), and inadequate talent of some students. Therefore, teachers need to pay attention to these issues and use social media to develop a better educating environment for individual learners.