Hi everyone.

I am typesetting a poetry text in triplets and I would like the second and third lines of each triplet to be indented (i.e., in the next example, verse no. 2, 3, 5, and 6). 

Is it possible to get what I ask for with ConTeXt?

The most I managed to do is this:

\starttext

\setupindenting[yes,1em]
\setuplines[indenting=even]

\startlines
Per correr miglior acque alza le vele
omai la navicella del mio ingegno,
che lascia dietro a sé mar sì crudele;
e canterò di quel secondo regno
dove l'umano spirito si purga
e di salire al ciel diventa degno.
\stoplines

\stoptext

but that's not what I want.

Thank you very much in advance?
Tommy