Hello!
I have recently started meditating seriously. I have tried open awareness, deep concentration, TMI... but I am not comfortable with samatha practices.

In a short practice course where I was taught the technique (I haven't had the chance to go on a retreat yet) I learned an introduction to the Mahasi method from the Ajahn Tong tradition, and they never stop labelling in the whole process of meditation.

I have noticed that labelling the rising and falling of the stomach generates calm and concentration.
When something comes into my awareness that distracts me, I label it and slowly the distractions are reduced and my concentration is increased.

With this method, is it possible, for example, to experience jhanas like in Samatha practices or is there a point where the calm and concentration cannot go any further?

Thanks

The object of concentration is not critical to samadhi. I don't see any impediment to moving from labeling the rising and falling of the stomach to jhana, once access concentration is reached. For me, restricting the labels to just rising and falling of the stomach would make it more likely. That said labeling would not be my first choice for getting to access concentration, and that sort of restricted focus would get in the way of the benefits of more open noting, but I have had the experience of unintentionally entering access concentration while labeling.  

Congrats! Welcome to the Dho.

So you are using the felt sensation of the breath at the stomach as your object of concentration and mixing in a repetitive mantra (labeling rising and falling) , very standard concentration practice.

This method you are using can easily get you into the jhanas. I would add to your practice the feeling of joy in the tummy as if you were on a swing set. This body bliss will tend to help you get up to the second jhana.
good luck,
​​​​​​​~D

Hi jms sc, best wishes for your future practice

Moving focus between changing objects develops momentary concentration (different from samatha stabilizing concentration)— you can get states with all the different jhana characteristics, but they will be less stable. This is much more likely to happen (and be noticed) in retreat, where there is continuity in momentary concentration & mindfulness. These "moments" can be sometimes longer than just a moment, but still there are 3c as long as you do vipassana; openness to the inherent instability of experience.

Labeling the most prominent object is not disturbing the concentration, it is a tool to increase the momentary contact with the object. So if there is calm, you just label that one. It is not important if you feel calm (in the vipassana training), it is just a mind state which we happen to like.

Calm can also be a sign of a mental switch-off; the rising/falling (or anything repetitive) can be mesmerizing, the mind switches to autopilot labeling, loses touch with the momentary experience. So make sure you don't neglect labeling any mind states ("calm", "joy") and perhaps the vedana ("neutral", "liking"). A monk said nicely: the primary object is not a cage for the mind, it is a parking lot. After you label a secondary object, go back to the primary (parking the car again) but open to leave again in the next moment.

It can be difficult to distinguish concentration and calmness; I get this sense from "the distractions are reduced and my concentration is increased". The mind can be uncalm, yet with high momentary concentration (being in contact with the changing uncalm mind moment-to-moment). There is no "distraction", there are just secondary objects of meditation, which you label and come back to rising/falling.

Do a retreat, if you have a chance. I did many in Ajahn Tong's lineage and don't regret (and go for one the next week ;)).

Great, thanks to all for the help!

Short addendum. There is the calmness of equanimity in vipassana as a stage of practice, which is different from concentration calmness (be it momentary or jhanic). Equanimity is calmness of non-reactivity, so no matter what comes, the mind stays calm (not by effort; but conditioned by prior efforts). This type of calmness is resilient, unlike the jhanic calmness, and can be much more stable in time (hours or days). It is what the mind is learning to drop into more and more often in daily life, through the practice.