There are currently two paradigms for term structure modelling: modelling the spot rate, and modelling the term structure of forward rates. Each has advantages and disadvantages: For spot rate modelling the question of model choice is unclear, while for most HJM models computations are difficult. We present a new class of term structure models essentially as general as either of the above and for which differences between models are easy to understand and, for a class of interesting models, computations are easy.