[MEI-L] accid/@ploc/@oloc vs. keyAccid/@pname/@oct

Roland, Perry D. (pdr4h) pdr4h at eservices.virginia.edu
Wed Nov 30 01:03:10 CET 2016

@pname and @oct are used to capture "logical" information for a pitched entity, such as a <note>, while @loc, @ploc and @oloc are for recording the "visual" location of an object with respect to the staff.

@loc uses a number-based approach where positive values are used for positions above the bottom line and negative values for the positions below. The value '0' indicates the bottom line of the current staff.  @loc = "4" indicates placement of an object on the middle line of a 5-line staff.

@ploc and @oloc also capture visual location, but in pitch terms.  In this case, the middle line of a 5-line staff using the treble clef is indicated by @ploc = "b" and @oloc = "4".  @pname and @oct could have been used for this purpose, but then it would have been difficult to differentiate between pitched items (those things that make a sound) and those things that don't make a sound by themselves, but need to identify their location in terms of pitch.

Some entities; that is, rests, permit @loc as well as @ploc and @oloc attributes, mostly to make it easier to accommodate translation from other representation systems that use one or the other approach.  Other entities; that is, accid and dot, allow @loc all the time, but @ploc and @oloc only when the MEI.mensural module is activated.  In the mensural repertoire placing these items according to pitch makes sense I'm told.

Since it has all the modules turned on, the mei-all schema is undoubtedly a source of confusion.  My recommendation is to use one of the other customizations instead.  Using mei-CMN for instance makes @ploc and @oloc unavailable on <accid>, thereby somewhat reducing the complexity of specifying a place for <accid>.

Hope this helps,


> -----Original Message-----
> From: mei-l [mailto:mei-l-bounces at lists.uni-paderborn.de] On Behalf Of
> Thomas Weber
> Sent: Tuesday, November 29, 2016 3:52 PM
> To: Music Encoding Initiative
> Subject: Re: [MEI-L] accid/@ploc/@oloc vs. keyAccid/@pname/@oct
> Am 29.11.2016 um 21:41 schrieb Roland, Perry D. (pdr4h):
> > The 20th-century exception you mention was the original intention behind
> using @oct.
> I see.  But why isn't @oct also used for <accid>?
> >
> > By "harmonizing" do you mean allowing both sets of attributes (but not
> simultaneously)?
> >
> IMO allowing both sets would be pretty messy.
> _______________________________________________
> mei-l mailing list
> mei-l at lists.uni-paderborn.de
> https://lists.uni-paderborn.de/mailman/listinfo/mei-l

More information about the mei-l mailing list