Ade wrote:
I'm having some trouble with the word "seunmhar", however, I'll offer this translation anyhow:
do scuab sé an trá bhí seunmhar
it swept the strand(/beach?) ...?
I like the idea of the broken harp's strings being like the bristles of a brush or broom, sweeping, but depending on what is meant by "seunmhar" it could well have extra meaning. It could be synonymous with "ceolmhar", and mean something like melodious. In this case the meaning could be something like "it swept the melodious strand", lit. "it swept the strand which was melodious".
Edit: eDIL's only use of "seunmhar" gives it as a form of "sénmhar", meaning prosperous or happy. So, perhaps:
it swept the strand [and it/he] was happy
seunmhar, old spelling for séanmhar = lucky, prosperous, happy