Here is a set of files from Sidekick 1/s era phones originally posted here:
Sidekick "new message" sound file
New Message.zip (25.2 KB, 4606 views)
Attention.zip (18.5 KB, 1244 views)
Blue Flute.zip (36.1 KB, 802 views)
AIM.zip (44.3 KB, 1127 views)
Bell Tree.zip (58.0 KB, 556 views)
Bird Call.zip (25.5 KB, 471 views)
Default Beep.zip (24.5 KB, 639 views)
Ding-A-Ling.zip (38.8 KB, 473 views)
Evil Overlord.zip (33.6 KB, 485 views)
Frogs.zip (25.1 KB, 427 views)
Future Ring.zip (74.3 KB, 578 views)
Siren.zip (43.7 KB, 497 views)
Wah-Wah.zip (42.7 KB, 530 views)
I have also posted the files here on my SugarSync account (similar to DropBox):
https://www.sugarsync.com/share/bt8m248oxzcbv
hope it helps.