Bg 1.13

tataḥ śaṅkhāś ca bheryaś ca
paṇavānaka-gomukhāḥ
sahasaivābhyahanyanta
sa śabdas tumulo ’bhavat
Synonyms: 
tataḥ — thereafter; śaṅkhāḥ — conchshells; ca — also; bheryaḥ — large drums; ca — and; paṇava-ānaka — small drums and kettledrums; go-mukhāḥ — horns; sahasā — all of a sudden; eva — certainly; abhyahanyanta — were simultaneously sounded; saḥ — that; śabdaḥ — combined sound; tumulaḥ — tumultuous; abhavat — became.
Translation: 
After that, the conchshells, drums, bugles, trumpets and horns were all suddenly sounded, and the combined sound was tumultuous.