David Ludwig's “Moto Perpetuo” shared the insistent drive of Paganini’s similarly titled “Perpetuum mobile,” though not much else. Where the Paganini thrives on speed and virtuosic display, Ludwig’s interest is in extending the violin’s palette with timbres and effects that would have been entirely alien to Paganini – who, like virtually all 19th-century composers, prized the warmth and richness of the instrument’s timbre – but are fairly common in contemporary music. 

Here, the violin tones bend, stretch, whisper, slide and rasp, and the virtuosity involved is both technical (its plentiful timbre changes occur speedily and relentlessly, often within briskly arpeggiated passages) and conceptual (the player has to make them sound chaotic on the surface, but also structurally coherent).

- Allan Kozinn, Portland Press Herald (08/09/17)