The Risset Rhythm exploits ambiguities in sound. The beat sounds as if it is always speeding up when it is not. It was created by Jean-Claude Risset and it is now known as the "Risset Rhythm" (Risset, 1986). This illusion provides us with an example of both an ambiguous stimulus and an experience of something impossible. It is an ambiguous stimulus for the speed of the rythmn played the first time round seems slower than the speed of the rythmn played the second time round, yet it is the same rythmn. The context of the occurence of the rhythm alters how it is perceived. It is also an experience as of something impossible for there could not be a beat that really continuously sped up and yet the notes remain as far apart as they seem to be.
Some modern music exploits the Risset Rhythm. For example: Astronivo & DJ Zombi's "Anything You Want" (Miki Litvak & Ido Ophir Remix) and Christian Smith and John Selway's "Total Departure" are examples (see the videos below).
Astronivo & DJ Zombi - Anything You Want (Miki Litvak & Ido Ophir Remix)
Christian Smith & John Selway - Total Departure
Typically, discussions of illusory experiences focus on visual illusions. But auditory illusions (and illusions in other sensory modalities, including cross-modal ones) are also interesting. Illusions in general provide us with cases in which what we experience doesn't seem to match reality. If that's right, we are not experiencing reality, and we can ask what it is that we are experiencing. If that's not right, then we can ask why we appear to experience something that doesn't match reality, and whether we really are experiencing what we take ourselves to be experiencing. Illusions in sensory modalities other than vision show us that this issue applies to experiences in other modalities, such as audition, touch, taste, smell, and so on.