The second way (but probably with a bracket as well as the number) is traditional. The first is gaining popularity. Both are acceptable.
A tuplet can usually be expressed as a whole-number ratio 'x in the time of y' where x is greater than y. I've heard the opinion that our example should be notated as duplet quarters, '2 in the time of 1½'. ...
Various contributors to this thread have suggested diverse solutions to this notation problem:
This is a bit pedantic, but it's sometimes seen. An experienced sight-reader should have no problem with this.
This is the closest to a 'standard' notation, and the most usual one. Leonard Bernstein uses this in the Prologue from "West Side Story". Orchestras ...
Let's start fresh and use a 2/4 time signature instead of 6/8. Now we'll have triplets in the first beat of the first measure, followed by a quarter note. Then the second measure will have two eighth notes followed by a quarter note.
I think this will give you more flexibility to play with different subdivisions and patterns as things progress.
I don't like either one of these. Especially if I expect someone to sightread it. One possibility that would probably be understood at sight would be to use a dotted eighth followed by a sixteenth tied to an eighth. (I cannot seem to paste graphics yet.)
The real problem is that the pulse has changed from 2 beats to measure to 4 beats (for this measure). A ...
AN alternative is as in your second example, but with two crotchets (quarter-notes) instead of quavers (eighth-notes). This accords with the convention that in an irregular group the notated duration is greater than the actual duration.
Unless you are one of King Henry's wives, you don't need to worry too much!! The '6' there is indicating six notes in the time of four. Like double triplets.Called sextuplets in the trade.
It looks like a slightly different font from the fingerings on the music stave - and again different on the tab.
The lower numbers are the suggested fingerings.