MidiStickers was developed “every-class” during three years of higher education academic teaching, evolving from real pedagogical challenges and 21th-century needs of core music curriculum reformulation. Inspired by active methodologies and hands-on musical training, its most inspiring use is helping students understad complex theory concepts that otherwise remain abstract in textbooks. With MidiStickers, students can perform music excerpts and visualize and compare figured bass, jazz chord symbols, german function theory and roman numerals, connecting more than 300 years of theoretical traditional in the same environment. Beyond visualization, students can also practice their keyboard harmony skills using auto-accompaniment generated on the spot, turning MIDI into a serious, integrated tool for formal music education and music labs.