When talking in spanish we tend to avoid pronouns since the verb already points out who the pronoun is refering to. particularly when talking about yourself we mostly avoid using "Yo" since it might sound a bit selfish (depending on the tone used when speaking) unless you want to stress the fact that it is your personal opinion. but we definitely use them, It's just a personal preference whether to use them or not when it comes to music, I think pronouns help to emphasize things (feelings for example) and some times they help to complete a sentence to make it rhyme with a previous one. I want to share with you a song that doesnt use that much pronouns (in my opinion), it's called Duele by Kalimba https://www.youtube.com/watch?v=8vFQ3_3ZB6Q Hope this helps :) Saludos