Tjyylli

I have identified three main problems holding back my piano sight reading, and this is the last of them.

Although I can play notes with the right timing by very slowly counting it out aloud ("1-2-3-4, 1-2-3-4..."), I have absolutely zero ability whatsoever to just play them right intuitively just by looking at the notation.

How can I get better at this?

I mostly play classical/romantic music like Chopin, Rachmaninoff, Debussy, Liszt, and Scriabin, as well as transcriptions of modern songs and movie themes. The timings are often very irregular.

Counting while playing is already the way to go! Be patient and don't give up. It will come.

I think what will help you is practicing to identify the big beats in a rhytmically complicated measure. Do it often just with the score, away from the piano. There's no shame in indicating with a small pencil line where every beat falls, for complicated rhythms you can even indicate the smaller subdivisions. When you know how the rhythm is built you can tap it out or sing it while concentrating on feeling the underlying beat. When you can do that, it's time to do it at the piano

Ofcourse while sightreading you can't take out your pencil to write on your score but if you do this regularly it becomes second nature and you will be able to 'see' these beats and their subdivisions instantly, when you see a complicated bar.

Try to start recognising common groupings of rhythmic values as patterns in their own right. This is a bit like moving away from reading one letter at a time when learning English to being able to recognise a whole word almost instantaneously in a single operation.

The way that halving a note value is often just a question of adding another beam or flag means that a crotchet followed by two quavers can be recognised as having the same duration relationships as a quaver followed by two semiquavers - so the patterns you learn can translate to longer and shorter levels of note duration.

The There are time inducations as andante, adagio etc. and even beats/min. advices.

So you can look up how many beats/min. an allegro ma no troppo would be and count the bars you have to play per minute.

But your problem seems to be a quite different one. All the time indications concerning the speed of music piece are only propositions to me. Sometimes I missuse a piece as a technical practice and play it in double
speed. Or even in performance I conduct it very slowly not to make angry the band members or the congregation, but the feed back can be complaining.

Some piano music I will never be able to play in the “correct” speed but I don’t mind at all. My goal is not to become perfect or be an virtuous but I would like to enjoy as many compositions as possible and improve my technic, my understanding of harmony and sight reading. I will be able to accompany a group or an ensemble or myself when singing and I know I will never be perfect. Perhaps this will help you to consider and reflect your own playing.

So if you are asking about this understanding of time - just compare different performances and listen to the different duration by different interpretations.

But if your problem is concerning the time signature and the rhythm you have to look up this SE site under sight reading and rhythm as there are already many answers and advices.