Tip #46 - Case Study in Subtle Notation Problems Resulting in MIDI Speed-Up

A MusEdit user recently sent in a score (linked as OrgPrblm.med below) in which some of the triplets were playing much faster than they were supposed to play.

It turns out there were a number of subtle notation quirks that were causing the problems, and these provide some useful examples of things to watch out for:

1) At the end of bar 2 the triplet above the tab line was actually inserted into the treble line. You can see this by turning off Mutual Translation (hit the button on the second toolbar, 7th from right) and then insert a space at the beginning of the treble line. You'll see all the triplets which belong to that line move, incuding the one that seems to be in the Tab line. This has the effect of "double-tripleting" the upstem notes so they go by faster than normal.

>> To fix it I clicked on the lower triplet once to select it, then hit Ctrl+X to cut it (delete it and save it on the clipboard) then I clicked on the top tab line to make sure I was in the tab line, then hit up arrow a couple of times, then hit Ctrl+V to paste it. I clicked on it to select it, and then hit up arrow a bit to finely adjust the position.

2) Bars 3 and 5 (line 2) both have the same problem as in (1).

3) Bar 6 has a double bar at the start of the treble line, but not in the tab line. This will cause the two lines to play out of phase, and that can often cause all sorts of timing problems.

>> To fix it I added a double bar to the begging of the tab line, then hit a backspace in front of the second bar in the line to keep the rest of the line aligned.

4) Even after doing that the timing was still off. Turns out the lower triplet was the same deal as in (1).

5) Even after fixing the triplet the timing was still off. So I looked at the situation more carefully: notice that in the treble line the triplet starts with a stack of three up quarter notes, but in the tab line there is one up quarter and two down quarters. The way MusEdit works is: when you have up and down stem notes on the same chord with a triplet above, the triplet will only affect the upstem notes. This way you can have a full duration DOWN stem half note lasting the same length as three upstem tripleted quarters. In this score in the top line all the quarters are up, so they are all tripleted, but in the tab line two of the quarter notes aren't tripleted. So basically you have different note timings in the two lines, and that often causes a speed up effect.

>> To fix it, (with Mutual Translation OFF since I only want to do stuff to the tab line) I double clicked on the tab chord so it was selected, then hit "q" to change the note type to all up quarter. When the "what do you want to do?" dialog came up I chose "Make all notes the same orientation"

6) Bar 12, the triplets in the Tab line are indeed in the tab line, but there's another timing mismatch between the treble and tab line since the bottom notes in the treble line are quarters, but in the tab line it's a half upstem. Because it's upstem, the half note gets tripleted, which causes a timing mismatch. It looks like it's supposed to be half notes in the treble line, so...

>> To fix it I put the caret next to the chord and hit shift+right arrow (another way to select a chord, since there seems to be a bug with double clicking when the document has been scrolled down! ...to be fixed soon) and hit "H" to change the note type. When asked what to do I choose "Only change notes with the same orientation" so the two down quarters turned into down halfs.

There's still weirdness in the tab chord though... so I put the caret next to the upstem half "4" and hit "H" to make it downstem half. Then I put the caret next to the downstem quarter 4, and hit "H" to make it downstem half too. Now the treble and tab chords look the same and the triplet plays OK.

7) There's another mixed up chord pair in bar 14, though it doesn't mess up the timing because there is an up stem quarter and downstem half in both chords.

8) Bar 16 looks like the last three quarter notes need a triplet. If they are tripleted as is, there'll be a timing problem with a bottom quarter being untripleted, but the top one being tripleted. Either change the bottom notes to half notes, or change all the notes to up quarters (as I did in this case).

I'm attaching the corrected version so you can see how these small changes made a difference. (Called FixPrblm.med)

(NOTE: Both the original and fixed versions were edited with version 3.0 of MusEdit. If you try to open these with an older version you might have a problem, in which case you may want to upgrade to a newer version of MusEdit. Send e-mail to info@musedit.com to find out how.)

Sample MusEdit files:

Original MusEdit file with notation problems

MusEdit file with notation problems fixed

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