B_Drummer Data Analysis
To see all videos and data pertaining to B_Drummer, follow the link below
The following post is about a particular drummer, named B_Drummer, who participated in the motion capture experiment for snare drumming.
B_Drummer Brief History
B_Drummer was a member of the Marine Corps Band. This is important to notate because of the manner in which Marine Bandsmen are taught and tested on the rudiments. Additionally, application of the rudimentary practice is at is core in the Marine Corps Band, or any other service band.
Protocol
Published papers on the data:
Snare Drumming Preliminary Results
Rudimental Coordination: From Snare to Set
The analysis of the 3 drummers who participated in the experiment are as follows:
1. Average of Position of Basic Strokes
2. Average of Position of Rudiments via basic stroke breakdown
3. Difference of positions based on basic stoke breakdown of rudiments
4. Overall analysis through triangulation of movement: Possible sin(x) or cos(x) reduction
Basic Strokes
The Rudiments are a subset of the Basic Strokes.
The Basic Strokes are a subset of the Positions.
Positions: Rest, Up, Tap
All trials are performed as alternating strokes or rudiments (when applicable).
The rest position is when a mode occurs in the data. While the mode for each anatomical marker vector differ in time, the time in which a mode occurs for all anatomical markers and vectors are close in time; meaning the rest position is reflected by the occurrence of the mode in a five number summary for a data set.
The up position refers to the maximum displacement value in the z (up and down) for the wrist specifically. While the origin of the stroke is at the shoulder (mainly from the scapula), the wrist determine the distance of the stick from the drum in the z-vector.
The tap position refers to the wrist when the minimum displacement value occurs in a sequence for the z-vector. This position in time is closely related to the stick hitting the drum.
The data for each drummer can be categorized by these three phenomena which map onto the traditional pedagogical terms used in snare drumming. The data is analyzed through this lens of maximum (up position), minimum (tap position), and mode (rest position). The other components of the five number summary used without a mapping of meaning to pedagogical snare drumming terminology.
Basic Stroke Types: Full, Up, Down, Tap, Buzz
Full Stroke: Rest->Up->Tap->Rest
Up Stroke: Rest->Tap->Up->Rest
Down Stroke: Rest->Up->Tap->Rest
Tap Stroke: Rest->Tap->Rest
Buzz Stroke: Rest->Up->Tap(n)->Rest
(n) denotes the number of times the stick makes contact with the head within one
stroke...
The following are the position for the basic stroke trail of the full stroke for the B_Drummer. The data shows through the standard deviation of each vector that the movement for this particular stoke is minimal. Due to the transformation matrix performed on the data, the median value of each anatomical marker and vector is either zero or approaches zero. This transformation allows for calculating the intersection and timing of anatomical markers as they move through each trial.
For the B_Drummer, the standard deviation of the resultant vector for all anatomical markers are below .5. This means that the movement produced by B_Drummer is consistent in this trial. A marked difference between the shoulder at frames 0-200 and 200-625. The shoulder completes a similar movement to that expressed in the other 3 repetitions of the full stroke, however the difference in the up position is .118cm (at frames 72 and 231) and the difference in the tap position is .18cm (at frames 109 and 287). An example of a distance between the up and tap position can be seen between frames 396-426 for .107cm. The difference between the marked distance and the example of an up to tap position (at frames 396-426) is .011cm. While this difference might seem minimal, the data suggest that this subtle movement effected the position of the other limbs in the resultant vector.
As seen in the chart above, the elbow in the resultant vector follows the shoulder in the resultant vector. The difference in the elbow's tap position at frames 111 and 255 is .696cm while the distance in the elbow's up position at frames 67 and 228 is .58cm. The distance between the tap and up positions from frames 392 to 440 is 1.081cm which is about the average distance between the up position and tap position for the 4 iterations of the full stroke for the right hand. The difference between the distance of the each position of the first and second iteration of the full stroke is about half of the distance of the an iteration of the full stroke itself.
A similar occurrence can be seen in the ulna and radius anatomical markers.
Tap Stroke: Rest->Tap->Rest
The Data can be seen here: Tap Stroke Data
The tap stroke starts at the rest position. The stroke begins once movement occurs. The concept behind the tap stroke is to drop the stick to the drum head; then catch the stick after the contact point which will return the stick and body to rest position.
There are 4 occurrences of the tap stroke. Since the tap stroke in these trials are performed with minimal movement, the analysis of this stroke time will also be minimal. Meaning, the up and tap positions are analyzed above.
Up Stroke: Rest->Tap->Up->Rest
The Data can be seen here: Up Stroke Data
The up stroke starts at the rest position. The drummer drops the stick to strike the drum. As the stick hits the drum, the drummer lifts the stick to the up position. Then, the stick and arm is returned to the rest position.
For the Up Stroke, B_Drummer has most of the displacement in the ulna anatomical marker. This particular trial similar in displacement with the Full Stroke trial; meaning, that the up stroke and full stroke are similar to B_Drummer in performance.
Down Stroke: Rest->Up->Tap->Rest
The Data can be found here: Down Stroke Data
The down stroke starts at rest position. The drummer raises the stick to the up position; then, drops the stick from the up position to the tap position. After the stick hits the drum, the stick is returned to the rest position.
There are 4 iterations of the down stroke found in this trial. The first iteration (frames 0-90) shows a marked difference in tap and up position for the Radius r-vector of nearly a half of the next iteration (frames 200-273). Additionally, the shoulder displays a minimized movement for the first iteration as compared to the other 3 iterations.
Buzz Stroke: Rest->Up->Tap(n)->Rest
The Data can be found here: Buzz Stroke Data
The buzz stroke starts at rest position. The drummer raises the stick to the up position; then, the stick travels to the tap position. As the stick hits the drum, the wrist and elbow allow the stick to bounce multiple times. At the a specified number of bounces, the stick is returned to rest position.
The buzz stroke for B_Drummer shows a shifting of the wrist from a separated sine wave to a continuous sine wave. This is partly due to the method B_Drummer is using to produce multiple bounces.
Conclusion
For B_Drummer, the shoulder seems to have a great effect on the rest of the distal joints (analyzed via the anatomical markers). For some instances, the shoulder performs in an oscillatory pattern.
Analysis of B_Drummer Selected Rudiments
Analysis of the Rudiments Via Basic Strokes and Positions
The analysis of B_Drummer for the selected rudiments during the experiment trials will be based on the positions (up, tap, and rest) as well as the stroke break down found in traditional snare drumming pedagogy.
Each rudiment trial has the positions cited in the analysis of the basic strokes throughout each iteration of the rudiment. Below is the basic stroke breakdown for each of the selected rudiments. All rudiments are broken down by stroke type.
Stroke Break Down for the Selected Rudiments
Ratamacue
(Left Tap + Left Tap) +Right Tap, Left Up Stroke, Right Tap, Left Down Stroke
(Invert for Left Hand Lead)
Inverted Flam Tap
Right Down Stroke + Left Tap Stroke, Right tap Stroke, Left Down Stroke + Right Tap
Stroke, Left Tap Stroke
The Flam Tap
Right Down stroke + Left Up Stroke, Right Tap, Left Down Stroke + Right Tap, Left Tap
Flam Accents
Right Down Stroke + Left Tap, Left Up Stroke, Right Tap, Left Down Stroke + Right Tap, Right Up
Stroke, Left Tap
Paradiddle
Right Double Stroke, Left Up Stroke, Right Tap, Right Tap
(Invert for Left Hand Lead)
Positions of the Selected Rudiments
Ratamacue (NO DATA)
(Left Tap + Left Tap) +Right Tap, Left Up Stroke, Right Tap, Left Down Stroke
(Invert for Left Hand Lead)
No Data for Ratamacue of B_Drummer
The Flam Tap (Data)
Right Down stroke + Left Up Stroke, Right Tap, Left Down Stroke + Right Tap, Left Tap
As seen in the chart above, the standard deviation for each anatomical marker and vector for B_Drummer is below .3. This means that the positions that B_Drummer articulates do not vary greatly. Again, this may be due to his time in the military band program as a drummer. There is an inconsistency with the relationship with the elbow and wrist from the last rudimentary trial (inverted) to this one (flam taps). Maybe the change from the up stroke positioning for the basic stroke sequence has an effect on the movement pattern of the elbow; and maybe this change effects how the transformed data anatomical markers intersect; but there isn't enough data to support that claim. However, the relationship of the elbow and wrist can be seen in the second graph below for the flam tap trial.
Inverted Flam Tap (Data)
Right Down Stroke + Left Tap Stroke, Right tap Stroke, Left Down Stroke + Right Tap
Stroke, Left Tap Stroke
As seen in the chart above, the standard deviation for each anatomical marker in each vector is below 1; meaning that the placement of the body in these positions varies very little for B_Drummer. This could be due to his time in service in a military band setting where rudiments are explored and exploited heavily. As seen in the graph below, the movement of B_Drummer can be seen clearly as an oscellatory phenomenon. Although there is variation in the sequencing of the intersection of anatomical markers for the transformed coordinates, the overall movement pattern through the positions are consistent as highlighted earlier through the value of the standard deviation for the positions in each vector.
There are few picularities with the B_Drummer's movement throughout the rudimentary trials. For the shoulder in the resultant vector, there seems to be a clear movement pattern. For the other two drummers (N and M), their shoulder movement resembled something of a chaotic nature rather than an oscellatory one. However, not enough evidence from this experiment is able to provide conclusive evidence on whether the movement of the shoulder is more efficient with a chaotic motion or an oscellatory one. What's also interesting is how the elbow and shoulder seem to share a more unison movement path rather than the inverse relationship seen in most of the trials for the basic stroke for B_Drummer.
Flam Accents (data)
Right Down Stroke + Left Tap, Left Up Stroke, Right Tap, Left Down Stroke + Right Tap, Right Up
Stroke, Left Tap
As seen in the chart above, the standard deviation for the position for B_Drummer in all vectors is .8. This means that there is consistency in where the body is placed when striking the drum and when lifting the sticks in-between strikes. As seen in the graphs below, the elbow and wrist share an inverse relationship in regards to position over time. Additionally, the shoulder seems to display a reoccurring pattern as well. This shoulder movement for B_Drummer is similar in all trials because of the somewhat strict oscillation of the movement. While the entire movement patterns of the wrist and elbow are not completely inverse, there are certain points when the inverse action occurs after an intersection of the transformed coordinates for all anatomical markers.
Paradiddle (Data)
Right Double Stroke, Left Up Stroke, Right Tap, Right Tap
(Invert for Left Hand Lead)
As seen in the chart above, the movement patterns of B_Drummer as it pertains to the manner in which he arrives to the positions is very consistent (based on the standard deviation of the positions). Again, the shoulder seems to have a set pattern for every occurrence of the paradiddle. Also, the wrist and elbow share more of an inverse relationship in regards to movement than the first two rudimentary trials.
Conclusion
There seems to be a consistent movement quality of the shoulder for B_Drummer that wasn't found in M or N. Without further data, nothing conclusive can be said about that phenomenon. B_Drummer's ability to achieve the lowest value for standard deviation of the position in all vectors and in all trials for rudiments and basic strokes may be due to the fact that he was military drummer who specialized in the rudimentary practice.