Here's an image related to my question: https://i.sstatic.net/zU0ZO.png
Below this image it says:
Bar 3 is incorrect, because the 3rd quaver in the group should have a stronger accent than the first quaver. The importance of the third beat of the bar is hidden.
So why is this a rule? Can't the musician hit an accented beat on the third quaver?
In the USA we tend to format phone numbers like this: 1(555) 412-1234 or 1-555-412-1234. Pretty easy to read right?
What about this: 15554121234
Same info but much harder to read.
This is the same. There is a unwritten rule that we use what I was taught to call “the imaginary bar line”. It is strictly for making the music easier to read by breaking things in to smaller more manageable chunks in a predictable way.
The same way you wouldn’t bar two eighth notes spanning over two measures (from beat 4 to beat 1) we also don’t bar notes between the 2nd and 3rd beat because there is an imaginary bar line that divides the bar in half.
I think there are other imaginary bar lines that take place in the measure when you are dealing with faster notes like 16ths and 32nds.
Check out here for more info:
It's 'incorrect' because in even time signatures, (4/4, 6/8 etc.) it's easier to read bars when they can be seen to split, physically, into two equal halves. Sadly, it's not always the case these days, but it definitely makes life easier.
Response to comments - keeping bars in two halves makes it necessary to use ties when something is syncopated. Some readers (inc. me) find that easier to see that there is indeed a syncopation.
Piiperi - from where I stand, the point of any written music is to make it as simple as possible for as many players as possible to be able to read it easily. If that necessitates keeping bars splittable into halves, then so be it. Of course, seasoned readers have no problems even 'reading fly excrement' (it's a muso phrase!), but why exclude the others, who need simplicity? Not sure that U.K.'dumb' is equivalent to yours...
I take exception to the part of the explanation which says the 3rd beat is emphasized. That's simply not true (except for rock music :-) ). In fact the beaming as written suggests the four eighth notes constitute a 'run' up to the 4th beat, and if anything the 4th beat would get some emphasis.
If you want the 3rd beat to be the strong one, then I would agree that the eighths should be in two groups, and probably put an emphasis mark of one kind or another over the first eighth note of the 3rd beat.
This rule I know in other words:
The middle of a measure (4/4 time) should be clear separated to be easier read and recognized. So it doesn't make sense to beam the notes passing the middle part of the bar. This is why bar 3 is incorrect.
As you can see the rule is concerning the notation, not the rhythm pattern. The rhythm of bar 2 and 3 are identical.
