When it is impossible to join the party and say happy birthday to your friends, it is a good idea to send them a birthday song with their names.
If you are good at singing, you can sing the birthday song and record it down then sent it to your friends, if not, you can customize a birthday song with your friend’s name.
On the 1HappyBithday.com website, you enter a name (such as Yuki in this post), and if which is listed in the result, then you can personalize a birthday song for the person, just as the following one for Yuki:
The website has offered 3,000 names, if you can’t find your friend’s name among them, you won’t be able to customize the birthday song.
By the way, in the end of the song, there will be a "1HappyBithday.com" badge, which you’d better remove before sending the song to your friends.
To remove the badge, you can use some audio editors (such as Aviary’s Myna), and then cut the last few frames. For example, the following is the edited song:
Isn’t it cool?