<p>I'm creating a (Java) class to represent an object in a musical score that has a specific onset time, and possibly a duration as well.  I need a good name for this class.  Is something like "Timed" or "TimedObject" appropriate?  I've tried to come up with something that ends in "-able" (like Runnable) but I can't think of anything good; "OnsetTimeable" sounds silly, because "OnsetTime" isn't a verb.  I don't really like "MusicalObject" either since that doesn't imply the object has an onset time (a "musical object" could be anything related to the score).</p>

<p>Update:  Musically, this class represents an abstraction of something that happens at a point in time in the score. This is supposed to be the superclass of classes like Note, KeyChange, MeterChange, DynamicMarking, TempoMark, etc.</p>

What is the main service (or services) your object is supposed to propose to the rest of your system ?
I believe its name should represents the
abstraction
you want to make by designing it in the first place.
So far, we know what your object is made of (an onset times, ...), but we do not know what is
does
, and more importantly as
baash05
points out, what it
is
: in a word, what it represents.
As mentioned in the question
What’s the best approach to naming classes?
,
the single responsibility principle
can also be a good approach.
If it must represent some common structure of any characteristics of a score (note, ...), a name like
ScoreAttribute
could be appropriate.