Let’s be honest - trying to describe what part of the body is pointing where in dance can get confusing fast. Especially when your feet are pointing one way, your frame another, and your travel vector a third. 😵💫
This problem has been addressed by the syllabus manuals 'Alignments' which didn't address the issue of the direction of your body segments (torso, head, feet etc). Over the decades it's become more and more obvious that a system was needed to help dancers understand where their Frame, Head, Hips etc should be facing.
Such issues are very apparent in CBM, CBMP, Promenade Position, Corte, Outside Partner and more.
You’re in Closed Position, facing Line of Dance (FLOD) - that means your feet are pointing down the room.
Easy, right?
But now imagine you’re in Promenade Position (PP). Things change:
Lets say your feet point Diagonal Wall (DW),
Your frame (torso) will be turned to facing Wall,
And your travel might be heading straight down LOD again (and yes, it feels like sideways)!
So how do we describe all of that without turning into spaghetti?
Don’t let the acronym scare you - SBAS is just shorthand for:
SBAS: Segment Based Alignment System
It’s a simple way to describe what direction your hips, torso, or head are facing relative to another body segment or the direction of travel.
SBAS is composed of the following vectors:
Tvec (or Tvec) is the alignment that the hips are about to travel or are already traveling in.
Bvec (or Bvec) is the Body's (or Torso, specifically the sternum) angular offset from your standing foot
Fvec (or Fvec) is the alignment specified in the various syllabi and also an angle with reference to the current Line Of Dance
Hvec (or Hvec) is the angular offset of your head with respect to your torso Bvec
Angles are measured in degrees to the left or right. Negative angles are to the left and positive angles are to the right of Tvec
Here's an example using head positions relative to the body:
| Head looking | Description |
|: ----------------- |: ------------------------------------------------------------------------------------------------------ |
| Left | As in Closed Position Hvec would be about -45o degrees with respect to the body. |
| Nose over Sternum | As in 'looking ahead' Hvec would be 0o degrees. |
| Right | Hvec would be about +45o degrees with respect to the body. |
Note: SBAS is local to the individual dancer which means that Leader and Follower are very likely to have different values.
It's a really good question so lets take a Waltz Box Step as Leader:
We commence Facing LOD (F LOD) and these are the steps (Sway, Footwork and Rise and Fall have been omitted). Yes there is an extended SBAS for Rise and Fall and Sway, we just omitted them for clarity.
| Step | Foot Position | Dance Position | Alignment | Turn | CBM | Count |
| :--: | --------------- | --------------- | --------- | ---- | --- | :---: |
| 1 | LF forward | Closed Position | F LOD | Nil | Nil | 1 |
| 2 | RF side | Closed Position | B ALOD | Nil | Nil | 2 |
| 3 | LF closes to RF | Closed Position | B ALOD | Nil | Nil | 3 |
Step 1:
Tvec is LOD because that's the direction we are moving
Fvec is LOD because that's where the standing foot is pointing
Bvec is 0o (zero degrees) as there is no body turn, it's a straight line.
Hvec is -45o because the head is rotated 45 degrees to the left with respect to the sternum.
Steps 2 and 3:
Things get more interesting, here's the chart with the SBAS values. To save space (and sanity) since this is all CP:
| Step | Foot Position | Dance Position | Align | Turn | CBM | SBAS | Count |
| :--: | --------------- | -------------- | --------- | ---------------------- | --- | ---------------------------------------------------------------------------------------------------------------: | :---: |
| 1 | LF forward | CP | F LOD | Com to turn L on 1 | 1 | Tvec = -22o
Fvec = -22o
Bvec = -22o
| 1 |
| 2 | RF side | CP | B DW ALOD | 1/8 turn L btw 1 and 2 | Nil | Tvec = -22o
Fvec = -22o
Bvec = -22o
| 2 |
| 3 | LF closes to RF | CP | B W | 1/8 turn L btw 2 and 3 | Nil | | 3 |
Step 1
Tvec is -22o since it's a 'commence to turn L' will have rotated the body creating CBM
Fvec is -22o due to the body rotation and CBM
Bvec is -22o because the body has rotated.
Step 2
Everything is the same as step 1 as it's an 1/8th turn which has effectively already been done. (See CBM)
Tvec is -22o since it's a 'commence to turn L' will have rotated the body creating CBM
Fvec is -22o due to the body rotation and CBM
Bvec is -22o because the body has rotated.
Step 3
Tvec is B W (or F C or LOD depending on what the next step is.)
Fvec is B W as the next step (step 4) will be backing (and things get more interesting)
Bvec is -0o because the sternum is an angle relative to the standing foot which in this case is zero. It's easy to check, just look down and your foot will be there :-)
| Step | Foot Position | Dance Position | Alignment | Turn |CBM | SBAS | Count |
| :--: | --------------- | -------------- | --------- | --------------------------- |--- | ---- | :---: |
| 4 | RF back | CP | B W | Com to turn L on 4 |4 | Tvec is B W | 1 |
| 5 | LF side | CP | P ALOD | 1/4 turn L btw 4 and 5, BTL |Nil | Fvec is B W | 2 |
| 6 | RF closes to LF | CP | F ALOD | BCT on 6 |Nil | Bvec is -0o | 3 |
Step 4
Tvec is -22o since it's a 'commence to turn L' will have rotated the body creating CBM
Fvec is -22o due to the body rotation and CBM
Bvec is -22o because the body has rotated.
Step 5
Tvec is B W (backing wall)
Fvec is -22o due to the body rotation and CBM. Note that moving foot is Fvec is -135o
Bvec is approximately -67o which is half of the 3/8 rotation. Remember this is with respect to the standing right foot which has also rotated -22o. Bvec is approximately facing F DC ALOD
Step 6
Tvec is F ALOD
Fvec F ALOD
Bvec is -0o because the sternum is an angle relative to the standing foot which in this case is zero. It's easy to check, just look down and your foot will be there :-)
Let’s say the Leader’s feet are pointing DW (which means the alignment is DW)
| Vector | Angle | Relative to |
| :------------------ | :---- | :--------------------------------------------------------------------------------------------- |
| Tvec | LOD | alignment in room |
| Bvec | +45° | With respect to the standing foot (Fvec). In this case the alignment would be W |
| Hvec | -45° | Sternum |
| Fvec | +45° | F DW |
and the first step **Tvec would be travelling LOD.
(Correct alignment and angles shown, there is no V-shape) to avoid breaking Frame.
Follower’s feet are pointing DC.
| Vector | Angle | Relative to |
| :------------------ | :---- | :---------------------------------------------------- |
| Tvec | LOD | alignment in room |
| Bvec | 0° | Standing foot. In this case the alignment would be DC |
| Hvec | +45° | Sternum |
| Fvec | -45° | F DC |
Note that as you step in Promenade
Suddenly you have an angle relative to something else that you can use to precisely position yourself. No more wondering WTH because the Manual didn't give the information you actually need to accomplish the figure.
Remember that negative angles are to the left and positive numbers are to the right'
SBAS makes it super easy to define what's going on - no need to know where you're traveling or even what step you’re on. Just look at another body segment and measure the angle from there.
This is especially important given the more realistic 'Realistic Alignment Chart'
We have chosen to have angles relative to the standing foot (Fvec) rather than Tvec because it's easier to see your standing foot. Look down and there it is.
Alternatively we could have used Tvec as the reference point which actually makes sense mathematically but is harder to visualize especially for Lunges, Corte's, Promenades, pivots and some turns.
One of the deciding factors relates to the established alignment tables being taken too literally. The more realistic map is the one actually being danced where the alignments are actually 22.5o either side of the 'ideal' angle. The only consistent reference point is the standing foot as ultimately everything else is based on it's position.
