Here you'll see, I monostitched a single line.

And yet, I found one line to be undefined,
thus, I wrote a couplet which is twice as long.

Of course, Wanna-Be poets, want to be read
so, to write but two lines would be a dread
thus, he continued with an added verse: a tercet.

As for the Fab Four, they wrote quatrains
day and night to be the delight
of any young lass that came in sight
sending them whirling about dervishly.

Still, if the need is greed
and you desire to write garrulously
writing five lines at a time changes
the last stanza to become a quantain
without creating much of a fuss.

That would come in writing a sestet
which tests your vocabulary further
perhaps, with love letter to Annette,
while smoking a pack of cigarettes,
a coquettish brunette, whose silhouette
reminded you of your mum Jeanette.

The problem is you have more to say,
seeing your feeling chatty today,
thus, musing further you add another line
changing a sestet to a septet, which is fine,
but be warned; do not go any further
or you will upset the Meisterburger
who has a distaste for octaves...

...requiring another sheet of paper
Psst. Germany's gone green