vielklang Instant Harmony is an instrument for easy generation of harmonies from an audio or MIDI melody. The utilization of voice leading and harmony progression models allows vielklang to create harmony parts in a more musical way than traditional harmony processors and makes it a versatile and creative tool for musicians, songwriters and producers. vielklang utilizes zplane's widely-used élastique SOLOIST engine for high quality pitch shifting and time stretching.