The Seeburg 1000 records play at 16 2/3 RPM which in most cases is only good for voice quality. The original “Talking Books” used by blind people were, for the most part, the only people using this super-slow speed. But back in the 60’s the Seeburg engineers came up with a way to squeeze a LOT of music on to a record going that slow. You can read about how they did it here.
Since the grooves were so small (400 per inch) it doesn’t take much to make a scratch or cause a pop or click. Also, unless the record is perfectly centered sometimes you will hear a record sound wobbly. The same sound can be heard when the rubber on the Seeburg 1000 turntable wheel starts to wear out.
Back in the days before the Seeburg 1000, this type of music was delivered over a dedicated telephone line. Music through a telephone line is pretty bad, so the ability to bring such fidelity to the industry was a major step forward.
Remember, the Seeburg 1000 is a Background Music System. It was never designed to be played though 600 watt home or car stereo systems at loud volume and 20-20,000 hz frequency response. It was designed to be played at low-level as mood setting music, much like Smooth Jazz is today.