Pen-Based Interaction for Intuitive Music Composition and Editing - Intelligent Music Information Systems: Tools and Methodologies - page 263

Figure 1. A tablet PC with a pen-based inter-
face

Finally, the user benefits from the traditional
computer functionalities; for example, a digital
musical score can be played, perfectly formatted,
archived, distributed, and so forth.
Actually, there are very few pen-based inter-
faces for digital document composition and edit-
ing, and in particular for musical notations. This
is due to the fact that developing such systems
is complex. Indeed, the recognition of symbols
drawn on the touch screen is a difficult problem of
pattern recognition due to the diversity of hand-
writing styles. This recognition process is even
more complex in the context of highly structured
document analysis, since these documents are
constituted of many elements of various natures.
Moreover, a same drawing can have different
meanings according to the context in which it
has been realized, which must therefore be taken
into account.
This chapter deals with the exploitation of
pen interaction to compose and edit structured
documents, and, more specifically, documents
with musical notations. Before going further, let
us introduce the vocabulary used in this chapter.
We use the word composition for the action of
writing music symbols, and the word editing
for the action of modifying one or more of these
symbols or more generally the document. We
designate as structured documents , documents
which present a predefined structural arrange-
ment, and for which it is possible to express
composition conventions , that is the way they are
classically drawn. Concerned documents come
from various domains, such as diagrams, plans,
electronic figures, and so forth. Traditional musi-
cal scores, plainchant scores, drum tablatures or
stringed-instrument tablatures are examples of
structured documents with musical notations that
we are going to focus on in this chapter. Online
interpretation deals with the interpretation of the
hand-drawn user strokes, which are the sequences
of points captured by the touch screen between a
pen-down and a pen-up. Online interpretation can
be either lazy (i.e., occurring only when explicitly

symbols the same way as on paper. The drawings
are recognized and retranscribed neatly directly
as the user composes the document. The user can
then check the recognition process and interact
with the system to easily modify the document,
for instance move some of its elements, erase
them, and so forth.
Pen-based interaction offers various advan-
tages for the composition and the editing of digital
documents. Indeed, the user can benefit from the
possibilities of both paper and computer systems.
On the one hand, the user can write symbols as
he usually does on paper. As stated by many au-
thors, like for instance Anstice, Bell, Cockburn,
and Setchell (1996), Macé and Anquetil (2006a)
or George (2003), it is more user-friendly and
faster than classical mouse-based composition
and editing systems which consist in clicking
on a menu to select a symbol and dragging it to
the appropriate place. Moreover, as presented
in Figure 1, a tablet PC is almost as mobile as a
sheet of paper, which simplifies its use in various
situations. On the other hand, computer systems
offer a direct retranscription which is easier to
read than hand-drawn symbols. The user can also
easily modify the documents, erase or move some
of their components, copy, cut and paste some
of them, and so forth, and then avoid the loss
of quality and neatness of the paper document.