You're right, TSTwizby, that there is no one answer to the question, but it's worth thinking about it from the point of view of the performers, listeners, and the conductor/director/teacher, and you, the composer. If you wrote a piece for full orchestra that was two minutes long, it wouldn't be enough of a piece to be worth an orchestra's time. They tend to have concerts built of symphony or concerto-sized chunks of music, so adding a two minute piece would feel odd. If you wrote a two minute piece for high-level solo pianist, that would also probably be too short to be worth someone's time. Recitals by good pianists are also generally composed of a few longer pieces, giving the audience and performer time to lose themselves in the music in between breaks for applause. But two minutes for a beginner pianist at their recital is a great length. It's about the limit of what they can prepare well and an audience of parents and grandparents can sit through if there is some fumbling. Two minutes is also great for a musical interlude in, say, the middle of a church service, where the music isn't the main event, but it adds to the emotional content of the message of the day. From your point of view as the composer, it's worth thinking about what kind of music you can write right now that will help you grow and keep you encouraged as a composer. Writing something too long as a beginning composer makes it harder to get feedback, because the number of casual friends willing to sit and listen dwindles with the time commitment. Long pieces can also get frustrating for you, because they may just be too much for you to handle well. Better to write something short and polished than something long and ragged. If you spend a few weeks working on a piece, and it's just okay, that's fine, and you can enthusiastically move on to the next piece without looking back, but if you spend 6 months working on a piece, and it's just okay, you're likely to feel like you have just wasted 6 months, and wonder if you should just give up on composing. There is a reason that creative writing classes start with poetry or short stories, not novel writing. Larger enterprises tend to expose the holes in our education quickly, and then we get disheartened. So keep it short for now, and you'll be able to polish each piece more, experiment with a different musical concept with each one, and all that effort will help you build larger structures on an increasingly sound foundation as you go along. Mainly, do whatever you need to do to keep composing exciting. To learn and improve, you have to keep going, so whatever gets you going is a good thing.