Do somebody know how to play music which was composed in the 15th and 16th century? Which notes are emphased? Are there sites in the net where we can get information how to play this music style?
I'd suggest to listen to recordings of good brass ensembles who are specialised in this type of music, e.g., Oltremontano or Concerto Palatino.
Here is a fine audio example by Oltremontano – by the way, when do we get cornett and sackbut VIs? Herb?
Renaissance music "works" best with legato playing and large-scale crescendos and diminuendos. Tiny baroque-style articulations are mostly inappropriate, and there aren't any single notes that are to be emphasised.