Digital Musical Instruments offer countless opportunities for musical expression as they allow artists to produce sound without the physical constraints of analogical instruments. However, by breaking the intuitive link between gestures and sound, they may hinder the audience experience, making the musician's contribution and expressiveness difficult to perceive. In order to cope with this issue without altering the instruments, researchers and artists have designed techniques to augment their performances with additional information, through audio, haptic or visual modalities. These techniques have, however, only been designed to offer a fixed level of information, without taking into account the variety of spectators' expertise and preferences. In this paper, we introduce the concept of controllable Level of Details (LOD) for visual augmentations. We investigate their design, implementation and effect on objective and subjective aspects of audience experience. We conduct a controlled experiment with 18 participants, including novices and experts in electronic music. Our results expose the subjective nature of expertise and its biases. We analyse quantitative and qualitative data to reveal contrasts in the impact of LOD on experience and comprehension for experts and novices. Finally, we highlight the diversity of usage of LODs in visual augmentations by spectators and propose a new role on stage, the augmenter.