Outside of a possibly problematic chapter on the Gospel of John, Barr provides a nice introduction to the New Testament in the vein of oral performance criticism.
The strengths of the book are it’s outline of the texts and subsequent breakdown of how the structure factors into the overall summation of it.
The weakness of this book is that Barr has a tendency to assume an oral performance position without real reason to. As well, the oral performance of the books ultimately fails to render any new meaning out of them aside from providing an alibi for seemingly contradictions in the Gospels.