Trey Anastasio of Phish, Billy Strings and Sturgill Simpson were among the special guests to join the band over three nights of concert and amid a city-wide celebration.

Fans of the Grateful Dead are pouring into San Francisco for three days of concerts and festivities marking the 60th anniversary of the scruffy jam band that came to embody a city where people wore flowers in their hair and made love,

In Grateful Dead parlance, this means oversized balloons full of nitrous oxide, offering concertgoers a quick high - one balloon for $20, two for $30. The deflated colorful balloons could be seen littering the ground surrounding the festival.