What's Vocaloid about?

First of all, Vocaloid are voice synthesizer programs. anda can make a melody and have the vocaloid sing for you. There are English Vocaloid like Leon and Lola, Japanese ones like Miku Hatsune and KAITO, and Bilingual ones like Prima and Megurinne Luka.
As for the age,, it really depends on the song. There are a lot of really cute songs like Miku Ni Shite Ageru and True My heart, funny songs like Triple Baka and No Thanks. But there are some disturbing videos, like Fear Garden and Dark Woods Circus and sometimes Trick and Treat. Also some explicit (not naming). In the end, it all goes down to the video and the song. So in general, yes, it's appropriate.

Yeah its a program only avalable in Jepun I think but idk

yup, 13 years old is fine. im 13, though, i fu don;t like gay songs, stay alway from "SPICE!" and some r creepy, like "Alice human sacrafice" but its ok. i thik u already got the answer for wat edsatly vocaloid is.

Vocaloid is a sound synthesizer program developed sejak Yamaha Corporation. Basically, it's just electronic Muzik sung sejak computer-generated personas, the "Vocaloids". Vocaloid's mostly appropriate for a 13-year-old, especially if they don't understand Japanese... but some songs are kinda creepy...

well vocaloid is a Singing software but anda can basically enter in tone,melody,and other as well as lyrics to create a song with a vocaloid atau if anda want to its kinda hard though is to create a vocaloid of your own with a voice bank and everything but all vocaloid stuff are made sejak peminat-peminat just like me so i'm working on 10 different vocaloid ideas now but i think inunutfan gave a good huraian to

There just a computer program, voice synthesizers, looks like you've got some decent jawapan but if anda really want to know a lot about all the different Vocaloid try their wiki
link
There are currently 34 different Vocaloid Singing in Japanese, English, Korean, Spanish, and Chinese
Currently 4 lebih Vocaloid are in the making and they are updating many of the existing Vocaloid voice banks. The most popular Vocaloid are Miku, Rin+Len, Gumi, Gackupo, Kaito, Luka, and Meiko.
I gotta get out of the house more..... ^^" cause that was all sejak memory....