What is this technique called?

They're just called bass notes.

I guess I have more reading to do... or finally pony up some dough and get a teacher. I read the portion on bass notes and didn't quite catch this. Oh well, thanks for the quick reply!

it's an old, old technique; playing the bass line and accompanying it. i've heard it called boom chick, alternating baseline, and travis picking, (and it's all sort of like the basso continuo of baroque composing) and here's tommy emmanuel demonstrating it with fingerpicks, but you can do it with a flatpick as well http://www.youtube.com/watch?v=WF9xobsf9hw
basically, all you're doing is playing the chords of the song with a bass accompaniment that you play along with it. the bass line usually consists of the notes of the chords you're playing and sometimes connecting notes between the chords, so you end up with walk-ups or walk-downs from chord to chord. the example you showed is a walk down from c to g. as you get into it, like tommy emmanuel does, you can also do more independent lines, or lines with other shapes and rhythms.

Its like the others say. Its playing the bass line against a definite strum pattern, while being aware of the time and count.

In this instance this uses a tie in a series of eighth note strumming. I realize that if you have no understanding of reading and counting strummed eighth note rhythms, this will not help, but this would be what you ought to try and learn. The guy is playing on the (1) of each chord change, as he moves down using chords, passing chords (chords which have the function of helping two chords join smoothly via voice leading) and inversions, in the key of C.

The basic count is 1....2 and ..... and 4 and... sometimes he's strumming it 2 passes per chord, and hitting the chords' bass note as he counts "1" on each chord change.

Best advice = Play each part slowly as you learn how to do this so that you are in complete control of your playing without mistakes.

Best,

Sean

Alternating bass line (or alternate bass) refers to a bass line that alternates between two or more bass notes for each chord, typically the root and the fifth. In the Emmanuel video Jason posted, he's using the root-third-fifth-third on a C chord starting at about 2:38.

Travis picking refers to a fingerstyle technique created by Merle Travis. Travis himself used only the thumb and index finger; almost everyone who followed him uses the thumb and two fingers to get the same effect. Travis picking is characterized by an alternating bass on beats one and three, and a syncopation of the notes in an arpeggiated chord on beats two and three, and occasionally on beat four. Emmanuel is doing that starting at about 1:16 in the video (you can hear the syncopation associated with Travis picking - without it, it's a different technique; what he shows later on in the 'lesson' part of the video isn't Travis picking, but a more basic style called the "Carter scratch", associated with Maybelle Carter)

Basso continuo is a completely different animal, and refers to a fixed bass line (which, strictly speaking, is an independent melody line in a polyphonic piece) and the notation includes "figured bass" - symbols indicating the chord inversion to be "realized", or improvised, by the continuo group... which was usually harpsichord, often accompanied by cello, and sometimes including other instruments. The continuo group played the bass line as written, and improvised a chord based accompaniment above it, guided by the figured bass notation.

None of those is happening in the original video.

I have heard the bass note/chord technique referred to as "boom chick". But I've also heard it applied to a lot of other things: alternating bass (as in the video Jason posted), jazz "stride" piano rhythms, alternating bass drum/hi hat on a drum set, etc. So rather than being descriptive of a specific technique, I think it's more of a generic term for a rhythm that alternates between two distinct sounds in any setting.

i didn't even watch the video. i just tried to remember the song from the mid 90s :) oh well, now you know more about bass/treble picking at least.