Case or theta-role term for object of performance?

In sentences like these,

* Kate sang a madrigal.

* We played four games of Go.

* I read "The Raven" aloud.

* The troupe performed "Hamlet".

-- it seems to me there's a common element the direct objects have;
they're transitory processes called into existence while the action
of the verb is being performed.  Rick Morneau classes these
kinds of verb arguments as "focus" as distinct from "patient";
they certainly aren't patients, but it seems to me they're also
different from objects-of-result as in

* Kate composed a madrigal.

* Edgar Allan Poe wrote "The Raven".

* What unknown genius invented Go?

* If Bacon wrote Hamlet, Shakepeare must have written the Organon.

This one seems to be a borderline case:

* Tom gave an extempore speech.

-- that is, it's a transitory result of a creative act.

In gjâ-zym-byn, recently, I've been marking these kinds of objects with
the postposition {ĉul-i}, from a root word meaning "performance,
recital, concert, show, etc."  Is there a standard
term in linguistics for this theta role or case?  Are there natlangs or
conlangs that consistently mark this role distinctively from patients,
and if so, what other theta roles tend to be marked with the same
case?  I've been calling it "performative case" in my notes, but
some quick research shows that "performative" may be in conflict
with uses of the same term in linguistics.

The Ithkuil grammar seems to identify the semantic role as "content"; I'm
not sure how standard a term that is, and I'm not sure it's specific
enough to refer to what I use  {ĉul-i} for and not much else.  I was surprised
to see how many semantic roles Ithkuil lumps into the corresponding
case, however; I had the impression, from the last time I studied Ithkuil,
that its case system was as fine-grained as gzb's postposition system
or more so, overall.  Probably it is, and this is a local exception.

>>In Sentence (2d) "Mary tells the children a story", Mary is a patient who
>>initiates the action which she herself undergoes, the telling of a story. The
>>children do not undergo an unwilled emotional, sensory, or bodily reaction
>>here, but rather are the passive and more or less willing RECIPIENT of
>>information, the role of an "indirect object" in Western languages. The
>>story, on the other hand, is merely a non-participatory abstract referent,
>>whose role is termed CONTENT.
The role of CONTENT also applies to the children in Sentence (2e)
"Mary wants children", where they function as the "object" of Mary's
desire. Since no tangible action is occurring, nor are the children
undergoing any result of change of state, nor need they be even aware
of Mary's desire, they are, like the story in sentence (2d), merely
non-participatory referents. As for Mary's role in (2e), the emotional
state of desire, being unwilled, self-activating, and subjectively
internal, creates a situation similar to an automatic sensory
perception or autonomic body response; thus, Mary's role is again that
of EXPERIENCER.

............

The OBLIQUE case ........... identifies the semantic role of CONTENT,
whether it is something given to a RECIPIENT, or the non-causal
abstract content of an experiential state, e.g., a memory recalled,
something desired, something feared. It would thus be used in
translating sentences such as Sam gave me a book, The child likes
cereal. It is also the case associated with existential
identification, what in English would be the subject of the verb 'to
be' when referring to the intrinsic identity or static description of
a noun as in the English sentences That boy is blind or The house was
built of wood. The OBLIQUE, being the semantically most neutral case,
is also the citation form of a noun (i.e., the form in which the noun
would be listed in a dictionary).
<<
http://home.inreach.com/sl2120/Ch-4%20Case%20Morphology.htm

In gzb all the CONTENT or OBLIQUE arguments in the sentences given in the text
quoted would be translated with different postpositions:

* Mary told the children a story:  {ĉul-i}, object of performance
(Mary: agent, children: target of communication)

* Mary wants children: {rjâ-i}, object of quest or desire (Mary: experiencer)

* Sam gave me a book: {ĥy-i}, patient (Sam: agent, me: target of
property-transfer)

* The child likes cereal: {mĭ-i}, topic (the child would be experiencer)

--
Jim Henry
http://www.pobox.com/~jimhenry/