"Testify" is an uptempo soul song by the American rhythm and blues group the Isley Brothers. Written by the Isleys and recorded in 1964, it followed several successful singles by the group and was the first single to appear on their own T-Neck record label. Music critic Richie Unterberger describes "Testify" as "a delightful track, one that worked as a both an out-and-out raver and a novelty", praising it as "tremendously exciting uptempo soul music". Jimi Hendrix provided the guitar parts, which Unterberger identifies as one of the best examples of his pre-Experience recordings.