premise: Jay Ferguson (born John Arden Ferguson; May 10, 1947) is an American rock/pop musician, known for his work with Spirit and Jo Jo Gunne, and his 1978 solo hit "Thunder Island". His later career has been as a composer of music for television programs and films.
hypothesis: Jay Ferguson is friends with Spirit and Jo Jo Gunn
reason: The context statement says he worked with them, but it doesn't specify if they were friends.