What Early User Involvement Could Look Like - Developing Technology Applications for Piano Teaching and Learning. - Tina Bobbe; Luca Oppici; Lisa-Marie Lüneburg; Oliver Münzberg; Shu-Chen Li; Susanne Narciss; Karl-Heinz Simon; Jens Krzywinski; Evelyn Muschter (Multimodal Technol. Interact., 2021)