“Real” bass vs. “Boom” — how do you know which?

Unless you are trained you probably need a Ratshack meter with some test tones and/or a program like EQ Room Wizard and a microphone + PC. The temptation is always to go for more bass than you should. However, you will hear more of the music if you get the bass right (even if it is not as impressive) because too much bass will mask higher frequencies such as the lower midrange and prevent you from maximizing the musical enjoyment.

Consider purchasing "The Sheffield Drum and Track Disc,"

Good suggestion - you can also get this on XRCD from Japan (they used the original master tapes which were made at the same time as they made the Direct-to-disc masters). The nice thing is that the first two tracks offer different examples of tuned drums. This way you can have a feel for where you system sits dynamically and how "tight" your bass is. Of course it would help to hear these tracks on a SOTA system to train yourself how it sounds.

Other tracks are, as suggested above, Chesky's Rebecca Pigeon "Spanish Harlem" with its nicely spaced bass lines - listen to see that all bass notes are of equally loudness (very useful for checking the critical 50 to 80 Hz range).

Other great drum tracks are: George Benson "Weekend in LA" Live "On Broadway" with Harvey Mason on drums. Also Keb'Mo's albums seem to have well recorded drums (unusually they have preserved the drum kit dynamic range on many of his tracks whereas typical rock/pop will crush drums with compresion/limiters). Another (but slightly bass heavy) great sounding CD is Dave Grusin "Hommage to Duke" - listen for balance in the bass riffs.

I'd also recommend funk music due to the heavy importance of drums and bass in this type music. Nils Landgren Funk Unit playing "Da Fonk" is a great one for the bass - very articulate. On the pop music side Peter Gabriels "Sledgehammer" has great bass which can be overpowering if you get it wrong but can sound "goldilocks just right" if you get your bass acoustics adjusted well.

If you get the bass right you will also find there is more depth to the soundstage - perhaps because you hear the lower midrange better and the "ambience" on the recording comes through.

When you listen to music and something sticks out ( say a particular bass note) then you have to ask yourself if it was intended or is a result of an incorrect setup. Usually recording engineers are msuicians and they try to keep everything in balance...

Nevertheless it takes a while to adjust to get used to "real" bass which can be subtle and understated. I

If you want to know if you have boomy bass just take a look at your waterfall plots!

You can see an example of a waterfall on my virtual system. It is simple to do but I suspect most "plug 'n play" folks (who consider a major upgrade to be changing an interconnect or a speaker cable) would find this approach daunting. "Nerds Only" applies! ;-)

I'm not a fan of using drum recordings since the bass drum will have one note pitch so will not offer the differentiation I look for.

Good point (although drum sounds are much more complex in their sound compared to typical instruments that follow harmonic rules). Drums do let you check the "transient" response - as this can be just as much of a problem in the bass as frequency response (although the two are tightly related because a high Q resonance of an underdamped speaker will create a broad frequency response hump as well as additional cycles of the woofer after the music has stopped, and although this broad hump can look mild when viewed with the eye it is actually very easily audible)

The key with drums is to listen for their own timbre (after the hit) and then the room echo (from the recording location) as well as your own listening room. If you can't hear this clearly (you don't hear the space around the drums) then you may have masking from an underdamped bass response... either from your speaklers or ringing from room modes.

Masking works upwards: Basically low frequencies wipe out your ability to hear higher frequencies - so if they last too long (resonance) or if they are overly loud then you'll miss stuff off the recording - simply put you won't hear it.

This is why warm resonant sound can pretty much fix a bad recording...it just lathers everything in resonance and hides imperfections that you might normally notice.