This study will enroll patients with Multiple Sclerosis and some difficulty with walking. The purpose of this study is to use Rhythmic Auditory Stimulation (RAS) a music therapy technique that provides rhythmic auditory cues (like a beat) to help improve a patient's movements, especially when walking.

Participants will be asked to participate in a walking program (WP) with Rhythmic Auditory Stimulation (RAS), or a WP without RAS.

Rhythmic Auditory Stimulation (RAS) is a music therapy technique that provides rhythmic auditory cues (like a beat) to help improve patients' movements, especially when walking. The RAS can be delivered at a fixed tempo or interactive tempo.

The device used in this study will deliver an interactive tempo. The equipment will include a mobile device app and sensors that are attached to the participant's shoes. Headphones and smartphones will be required to use the device and will be provided to the study team and kept at the center for this study. The device is designed to use audio cues to facilitate improvements in the participant's walking speed while listening to music.

The overall purpose of this study is to assess the safety and acceptability of interactive RAS music combined with gait training in individuals with MS and walking impairment, and to gather preliminary efficacy data for future studies.

Inclusion Criteria:

• Diagnosis of MS based on 2017 revised McDonald criteria (relapsing or progressive course)
• Performs the T25FW in 8 to 30 seconds (cane(s), walking stick(s), crutch(es), or wheeled walker allowed)

Exclusion Criteria:

• Physical therapy in the past 3 months or immediate need for PT due to safety concerns (e.g. falls)
• Requires at least one seated rest during the 6 MW test
• Treatment with high-dose corticosteroids in the past 2 months or planned during the study period
• Lower extremity botulinum toxin (BT) injections for spasticity in the past 3 months, or planned during the study period
• Initiation of an oral symptomatic therapy which could affect walking in the past 4 weeks (particularly dalfampridine and medications for spasticity)
• Initiation of a new disease-modifying therapy for MS in the past 3 months
• Comorbidity compromising safe participation or affecting walking (e.g. uncontrolled cardiac or respiratory illness, musculoskeletal disorder)
• Severe hearing impairment with or without the use of hearing aids, such that the participant cannot hear the rhythmic music stimulus consistently.

Inability to walk safely to the rhythmic music stimulus during the baseline visit.

A blinded examiner will be used to perform the gait analysis, 6 minute walk , and timed 25 foot walk