why people don't hold their attention?
Great question. If you ever find a definitive answer for this let me know
Seriously, all composers (even those with great experience) struggle with this everyday. There's no template and it ultimately depends on the piece and the listener of course.
@MarcusD has some great comments in your other thread. Especially when he says:
Ask yourself how to make it more interesting
Put your pieces aside for the moment. You need to be able to listen to other music you find interesting and abstract underlying principles of compositional approach and apply them (when appropriate) to your own works. Ask yourself why you like a particular piece? What about the piece draws YOU in and holds your interest?
Listen to this piece as an example.
Granted it's a different style and is intended to be paired with picture but the general principles are there in the beginning. See if you can transcribe the first minute of it in your DAW. You will notice:
He could have just started with the drums/rhythm but he didn't. He opened with a short tempo-less section having the cello play a line with trem into gliss into trill over a low drone. This, for me, grabs interest.
Then before I can get bored, the drums immediately come in and introduce tempo. Notice the rhythm contains additional interest with the simple use of accents. Why play the rhythm with the same velocity throughout? But that's not all. Higher strings come in at the same time with a quiet trem which adds an extra dash of change.
Then before that can get boring we get a slight crescendo into an impact. Now low strings and brass join the drums (accentuating only part of their rhythm) and the main melodic idea (a simple one) is introduced. Dynamics continue to increase, harmonies begin to thicken until a huge dynamic change happens and we have stronger tempo through ostinato and a more climactic feeling with the whole orchestra playing. Soon the wider frequency spectrum begins to narrow, the dynamics begin to soften and we are back to a tempo-less section. Soon it will build again. These series of simple peaks and valleys (of dynamics and frequency) is the overall driver/arc for the piece.
Again, this is a different style of music than what you wrote and the changes come more rapidly then may be appropriate for your piece, but the underlying principles of continued interest through slight change built upon what came before are there, can be discovered through analysis and applied to your compositions going forward. And his ideas are tasteful and well executed. He knows how to set a mood and build drama.
Djawadi creates continued interest in the first minute mainly through changes to tempo, timbre, dynamics as well as vertical development (layering new motifs over the existing ones) as opposed to major changes to harmony, key, melody, etc. You may wish to focus on changes to the latter three. Or maybe all of them!
Perhaps your music could start with a tempo-less section or instead of having strings join the opening unison ostinato with the exact same rhythm, perhaps they could break up the rhythm, accentuating certain parts of the original ostinato, which may create more interest. Perhaps they could introduce more rhythmic complexities to the initial rhythm. Maybe you could start to thicken the harmonies gradually (as happens in the Dragonstone piece) instead of just having the ostinato remain a two part harmony. Then again, maybe all my ideas are bad and you'll find a better way to create continued interest. My point (and
@MarcusD) is you should stop to ask yourself, what would make this more interesting? Push yourself. Get ideas from others (by analyzing their music), etc.
Also, let your music (especially phrases) breathe. Don't feel like you have to fill the time/space constantly. Things can become laborious for the listener otherwise.
It's fun thinking of all the different ways we can add continued interest to music! Have fun with it!
Read the book below when you get time. It may not address everything you're looking for specifically but I think it has some great info and will open your mind to new ways of approaching composition. And it's free!
https://alanbelkinmusic.com/bk/F.pdf