I can only applaud the effort the students put in. I can only add to comments below and hope it helps them. Practice long note playing and ensure the band are warmed up and fully tuned before starting to play. Get a tuning device, they are better than ears. If this issue is sorted, you will improve and all the band will notice.
Desafinación total, canciones bastante olvidadas, tienen buen entusiasmo deberían enfocarlo en tener una afinidad y estructurar bien las canciones, lit hay pedazos de canciones que no tienen sentido, no se entiende, crítica constructiva