[HANASHIR:10337] pronunciation leeway?

[H & R Shubert <notfranz...>]

Thanks Erik, for the concise explanation of Hebrew accents.  Looking at how 
words fit into melodies, I notice ADOnai (in Adon Olam, Silverman's Mi 
Chamocha), CHAYim (in Etz Chayim Hi),t'HOrah (in Debbie's Elohai Neshama), 
b'AM'cha (in Richards' R'tzei).  In none of these cases is the metteg on the 
accented syllable.  My question is:  is there some acceptable leeway in 
accenting syllables to fit melodies?  
Thanks,
Rachelle