Quantitative movement analysis.
In addition to qualitative analysis techniques
such as the Labanotation and Laban Movement Analysis,
there are also numerous methods of technologies
for numerical recording or music-related motion,
or what is often called motion capture.
Very generally, we will talk about two main types
of technologies.
We have the camera-based systems and we
have the sensor-based systems, and each of these
have a few subcategories.
First we are going to look a little bit more
at the camera-based systems.
The great thing about cameras is that they
are an easy, fast, cheap, and not the least available
solution to working systematically
with the study of music-related motion.
Nowadays everyone has access to high quality video cameras even
in their mobile phones, and the cost
of professional quality video cameras
is also within the reach for many.
But in the world of motion capture,
there are many other types of camera-based systems
beyond the regular cameras.
Here we often talk about two different types of variables
that we need to take into account.
The first one is whether we are going
to use cameras that capture the same thing that we see--
that is, regular light-- or use cameras that record,
for example, only the infrared light.
Infrared cameras can, for example,
be very useful if you want to study
people dancing in a dark club or other types
of dark environments.
The second we need to think about
is whether we are using markers on the body or not.
Markers can help identify people or specific body parts
in a much more detailed way than a marker-less system can.
Of course, putting markers on the body
makes the whole setup much more complex.
We're later going to look at demonstrations
of how both regular cameras and the more
advanced camera-based motion capture system
can be used to capture human motion.
But first, let us talk a little bit about sensor-based motion
capture.
Sensor-based systems are built around sensors.
And here, again, there are a number
of different types of technologies
such as acoustic sensors, mechanical sensors,
magnetic sensors, inertial sensors,
and electrical sensors.
Common to all of these is that they
require to be put on the body of the people
to be studied, which makes them less
attractive for many musical applications.
However, as the technologies are constantly
getting smaller, faster, and more reliable,
they are still very interesting to use also
in a musical contexts.
In this course we will demonstrate
only one type of these systems-- the inertial ones.
But first, to conclude, there are a number
of analytical approaches and technologies
available for studying music-related motion, ranging
from qualitative to quantitative,
from cheap to expensive, from small to large,
and from simple to advanced.
It is impossible to give one answer to what type of method
or technology to use.
They all have their strengths and their weaknesses.
For that reason, it is important to decide on the right analysis
method for the question at hand.
And the, perhaps, most important factor
that should be taken into account
is whether to work in a controlled laboratory setting
or in a more ecological setting such as a concert hall.
This will, to a large extent, guide
which methods and tools to use.
We can say that more specialised motion capture
systems, like, for example, infrared
marker-based systems or the electromagnetic systems,
and various types of inertial sensors,
often provide the highest recording
speeds and also a very high spatial accuracy and precision.
But such systems also come with several drawbacks.
Price is one, although such systems have quickly
become more affordable.
More problematic is that the person being studied
has to wear markers-- sensors on the body-- something that
may be both alienating to the performer and obtrusive
to the motion being performed.
This is particularly problematic when
using electromagnetic and mechanical systems
with fairly large and heavy sensors and cables.
But also the lightweight reflective markers
typically used in optical infrared systems
are noticed by the performer, albeit to a lesser degree.
The perhaps biggest challenge with the larger systems
is the non-ecological setting they require,
while small inertial systems, on the other hand,
can be mobile, wireless, and more or less invisible,
although the physical sensors need to be placed on the body.
So if the aim is to study musicians in the real world
concert situation, playing video recordings
may be the only realistic solution.