There are two types of music I will discuss somewhat briefly in this post, and they are bluegrass music and Celtic music.
Bluegrass is truly an American music, developed naturally in the heartland of the USA during the early 20th Century.
There is a lot of religious content in the bluegrass style, typically featuring a strongly Christian viewpoint (“I’m working on a building, it’s a Holy Ghost building”) but this sits in stark contrast to the rural blues, which of course tended to be far more secular and often featured covertly sexual themes (“another mule been kicking in your stall”, “rock me all night long”, and so forth). Enough about the blues – back to bluegrass, which is largely unrelated to blues other than belonging to the time period in which they both first developed.
Bluegrass is a rich part of the tapestry of American “folk” music. Farm workers and their families would be entertained at country fairs and the like by the traveling musicians who developed this style. Most prominent amongst them was Bill Monroe, regarded today as the undisputed father of bluegrass.
William Smith Monroe was an American mandolinist born in 1911 in Kentucky. The genre got its name from his band, the “Blue Grass Boys”, named for the famous blue grass of Monroe’s home state, which is for the most part horse and farm country. The usual repertoire includes songs of theirs such as “I’m Working on A Building” and “Blue Moon of Kentucky”, the latter tune famously covered by the young Elvis Presley in the late 1950’s as one of his very first recordings.
Celtic, on the other hand, consists of the folk music and storytelling that originated from, for the most part, Ireland and/or Scotland, but anywhere these folks have settled on the planet has benefited from their wonderful musical heritage. Once again, it was a great way for the workers in rural areas to let off steam. Since so many people emigrated from these places to the USA and Canada during the past few centuries, it has become a vital part of the East Coast scene, mostly in Canada but to a lesser extent in the USA. Anywhere there is an Irish or Scottish community you will hear a lot of this music played.
Bluegrass and Celtic music feature differing instrumentation. For instance, you might hear plenty of banjo in bluegrass, but rarely does it get used in Celtic music. On the other hand, you will hear bodhran, a hand-held drum, and the Uillean pipes (the main featured sound in the movie “Titanic”) when you listen to Celtic music, but these instruments are not too likely to be heard in bluegrass. Areas of common ground certainly do exist, for instance the fiddle, the mandolin and the acoustic guitar all feature prominently in both musics.
These are natural music styles, played acoustically without amplification for the most part. In today’s modern world, we are used to hearing amplified music, and at larger venues it is essential, but clearly these styles developed in a world where amplification either had not been invented yet or was not required. Consequently, the kind of sounds you expect to hear are usually acoustically generated.
The bluegrass revival in recent years has increased the number of people who are trying to record this style of music at home. It takes little equipment, but it takes a fair bit of knowhow to get a good sound. Often, one or two large-diaphragm condenser microphones and/or a quality large ribbon microphone is all you need to deploy, together with acoustic treatment for the space.
You will get generally good results from a wooden floor below the performers, and a reasonably high ceiling. Plywood sheeting can be placed around the players as temporary walls or on the floor, and this will enliven the sound of guitars, fiddles, mandolins, the acoustic bass and even the voices nicely.
If it is too reflective in the space, and too live-sounding, or it is sounding a little “boxy” in the midrange, you will want to deploy a mattress, duvet, quilt or blankets to take some of that edge away.
There are usually no overdubs, so it is an “audio snapshot” of a live performance in almost every case.
It’s important to remember this is an organic, authentic sound, usually performed in public by musicians clustered around a single microphone, balancing themselves acoustically in order to achieve the classic blend of voices and instruments that is so much a part of the history of the music.
It is usually the simple use of a large-diaphragm condenser microphone such as a Neumann U87 that gets great results for this sound. Allow the musicians to balance themselves in the room, and avoid using headphones. Headphone spill into open microphones is very undesirable.
Placing the microphone into omni mode, or possibly into binaural (figure-8) mode where appropriate, should give you faithful results, but omni will pick up headphone spill more than any other pattern. On the other hand, there is no possible off-axis placement relative to an omni mic since it picks up in all directions equally, and the worst thing about spill is that it usually sounds odd, boxy, hollow, or otherwise unnatural due to being picked up off-axis from a cardioid-based pattern.
Gathering around that microphone appropriate to the selected pickup pattern, you allow the performers to balance themselves. This is reminiscent of jazz trios and the like, where the mix is often more to do with the artists at the time of recording than with anything the engineer would do mixing later.
One of the most likely areas for problems is the acoustic upright bass, which is the normal low-end instrument in bluegrass. The electric bass is not found in the traditional bluegrass sound.
Using a large-diaphragm mic near floor level, two feet or so above the ground, aimed at the bass from a foot or so away is often a good solution, but you need to be conscious of how noisy people are with foot-tapping and the like. You could also wrap an SM57 or similar in foam and wedge it into the bass behind the bridge, which would give you less low end but also less leakage from other sounds.
There is also a large likelihood of phase issues occurring between the main mic at voice height and the lower bass mic when their signals are combined in a mixer. Moving the position of the bass mic in small increments, say half an inch at a time, and checking for any phase cancellation when summed to mono is essential. See my earlier post on recording bass, where I go into a lot of detail about phase issues.
The fact that so much of the sound, usually all of it, is generated acoustically without an amp means that it is very sensitive to microphone choice and positioning. A lot of time may need to be spent moving people around the microphones, or moving the microphones around the people. This pays off when you hear the blend you need, so do persevere and pay close attention to what you are hearing.
The mandolin, the fiddle and the vocal harmonizing all form a large part of the blend, and these can be captured through the same microphone that is positioned to record the singing. Trial and error is the solution here. Do a number of takes, and with each one, examine the results and make appropriate changes to the mics or positions.
Try not to use any EQ, since the more you skew away from a flat EQ setting, the more unrealistic and unnatural your results will become. Read the previous sentence again to be sure you remember this.
Flat EQ definitely is the best way with this music, but you may find a little top end ‘air’ helps with clarity, perhaps a subtle shelf boost of one or two dB at 16kHz or higher. Too much here and you will get screechy or nasal fiddles and mandolins, so be very subtle if you must switch in the EQ controls. Avoid digital EQ plug-ins if at all possible, since they are far less flattering than analog tube EQs for this music.
Celtic music usually includes percussion instruments like the tambourine or bodhran and may well benefit from overdubs for this reason, but it is less common in recording bluegrass to face this issue.
Summing up, the best tools you have for recording Celtic or Bluegrass music are your ears, your microphones and your patience for some trial and error takes and playbacks.
As always, listen closely to the music and then the answers to the problems of recording it will soon present themselves. It is mostly about preserving and highlighting the blend that is made in the room by the musicians in performance.
Next up will be a post on tracking background vocals, and that will be followed by a post on tracking lead vocals. See you there!