Ключевые слова: adult, background, chalk, chalkboard, class, classical, classroom, closeup, coach, college, composition, education, green, greenboard, hand, harmony, instructor, instrumental, knowledge, learn, learning, lesson, lifestyle, male, man, melody, music, musical, musician, note, notes, person, piece, professional, rythm, scale, school, singer, song, student, study, teacher, teaching, training, university, vocal, writing,