I've read that before about it having to match the old Sony U-matic recorders - not Betamax as he says as that was a consumer format - but I don't know if it is really true.
EDIT - no I'm wrong and he is right, it was Betamax:
Betamax also had a significant part to play in the music recording industry, when Sony introduced its PCM (pulse-code modulation) digital recording system as an encoding box/PCM adaptor that connected to a Betamax recorder. The Sony PCM-F1 adaptor was sold with a companion Betamax VCR SL-2000 as a portable digital audio recording system. Many recording engineers used this system in the 1980s and 1990s to make their first digital master recordings.