Guess The Genre #2838 (Gathered by Ken Anderson)

RCA_JVCQuadradisc RCAVIctor_4ChannelDemonstration
Astor_4ChannelSound Columbia_SQQuadraphonic
WarnerElektra&Atlantic_Quadradisc WarnerAtlantic_QuadraphonicExperience
Columbia_Motorola4ChannelStereo Pye_QuadraphonicSampler
Columbia_RealisticFullSpectrum Pioneer_FourChannelRecord

Answer: Vinyl Quadraphonic Samplers - Next is Guess the Genre #2839

Or, I don't want to guess - Show Me A List