Healthy volunteers, and patients diagnosed with HIV or fibromyalgia will complete 4 rounds of QST testing; baseline + 3 music conditions to determine effect of music on pain sensitivity.

The music intervention (Unwind), developed by the investigators collaborators at the Sync Project, is a machine learning protocol that generates specific sounds and phrases of music that are stitched into a music track in response to user-reported pain, anxiety and catastrophizing scales. Unwind is delivered via a web application on a smart phone.

Participants will also listen to white noise and their favorite music throughout the study session

Pressure algometry is the most commonly used test for static mechanical pressure sensation in the skin and in deep tissues. Pressure algometers deliver a firm and quantifiable pressure through a flat base applied to the skin. The electronic pressure algometer that we will use (Wagner Instruments) is a hand-held algometer utilizing a pressure-sensitive strain gauge, covered by a 0.5 cm2 circular probe. The probe is covered with a soft polypropylene disk, to avoid injury to the skin. The pressure applied through the probe is transduced, amplified, and converted to electrical reading on a digital display. The pressure will be slowly increased (1 lb/s) and the participant will be asked to note when they first feel pain and when they want the pressure to stop , which will be recorded as the pressure pain threshold and tolerance, respectively. This process will be repeated on the trapezius and the forearm, alternating between sides of the body with 20 seconds between measurements.

Will be assessed using standardized weighted pinprick applicators using a range of forces (128 mN, 256mN and 512mN) which result in a painful sensation in most subjects. First, a single stimulation of the lower force pinprick will be applied to the dorsal aspect of the index finger between the first and second interphalangeal joints of each hand while resting palm down on the armrest, and then rated by the subject on a scale of 0-10. The weight probe that induces at least some pain, but not more than 3/10 pain will be determined, and this probe used for repeated testing. Then, a train of 10 stimuli will be applied at the same spot, at a rate of 1 stimulation/second. The subject will rate pain on a scale of 0-10 after the first, fifth and tenth stimulus, then rate any ongoing pain 15 seconds after cessation of the last stimulus (painful after-sensations). Temporal summation will be calculated as the change in pain score between the highest and lowest pain ratings in a train.

Will be assessed through response to cuff pressure algometry (CPA), in a similar manner to our previous studies.123 Tonic, deep-tissue, mechanical stimulation will be applied using a rapid cuff inflator (Hokanson) wrapped around the leg, centered around the middle of the gastrocnemius muscle. Pressure will then be increased at approximately 5-10 mmHg/s, at which time participants will be asked to note when they first start feeling pain and then when they feel as though the pain is a 5/10. At this point the cuff will be deflated. Participants will be given a 30 second break. The cuff will be re-inflated to this previously identified pressure and held for two minutes (or until participant asks to stop), at which point the cuff will be deflated. Participants will be asked to rate their pain every 30 seconds, as well as to rate any painful after sensations. Temporal summation will be calculated as the change in pain score between the highest and lowest pain ratings in the 2 minutes.