Listening to music when one is put on hold

If you have the choice and are able to remove this evil,
then do so. If the matter is beyond your control, then you will not be held
accountable, so long as you do not deliberately listen and enjoy that, because
music is haraam (see Question #5011).
The same applies to singing, because Allaah says (interpretation of the meaning):

“And
of mankind is he who purchases idle talks (i.e. music, singing) to mislead (men)
from the path of Allaah without knowledge…” [Luqmaan 31:6]

Ibn Mas’ood said:
This refers to singing. Similar views were narrated from others among the Sahaabah
(may Allaah be pleased with them all) and the Salaf. Shaykh al-Islam (Ibn Taymiyah)
differentiated between listening for the purpose of enjoyment enjoyment, and
unintentional hearing where one has no choice in the matter. In the latter case
there is no blame or sin involved, and Allaah does not burden a soul beyond
its scope. If the other party puts you on hold on the phone, then try not to
listen to the music as much as possible. Beware of actively enjoying the music,
and seek the forgiveness of Allaah, for Allaah is Oft-Forgiving, Most Merciful.