You nailed it! FWIW, I've got a Zoom H4n that I've used to record trains and thunder (complete with buzzing and chirping hummingbirds) and actually gotten much better results than that album. Technology marches on. ;-)
These days I use an Avantone CK-40 stereo condenser with a Marantz PMD-661, recording in mid-side, and dematrixing in post production. Reasonably portable when both are mounted on a mounting bar of my design, on a lightweight tripod.
Unfortunately, I didn’t have the recorder with me on the 4th, so I took pics and a few movie shots with my Canon SLR instead. Would’ve been great to record some double-system video, for a change.
Used to have a slew of AKG mics (CK460s, CK414s, and a CK426 stereo) with PCM recorder and later, DATs. All back in the day when I was doing a lot of concert recording and a little broadcasting.