A group of young people sitting in the grass as one plays a guitar and another the violin .
A group of young people are in the grass .
A group of young people sitting in the grass as one plays a guitar and another the violin.
A group of young people are in the grass.
There is a group of young people in the grass area.  It might be better stated that they are on the grass.
There is a group of young people in the grass area . It might be better stated that they are on the grass .