What is the test for a concurrent or consecutive sentence under section 669 of the Criminal Code?

Generally, section 669 grants the trial court discretion to impose concurrent or consecutive terms. "It is well established that a trial court has discretion to determine whether several sentences are to run concurrently or consecutively. [Citations.] In the absence of a clear showing of abuse, the trial court's discretion in this respect is not to be disturbed on appeal. [Citation.] Discretion is abused when the court exceeds the bounds of reason, all of the circumstances being considered. [Citations.]" (People v. Bradford (1976) 17 Cal.3d 8, 20.)