On the page:
http://www.movabletype.org/documentation/installation/detailed-instructions.html
the instructions for installing the MySQL database "using a shell", say:
>>>
If you have shell access to your Web server, you can use the mysqladmin utility to create a database. Enter the following command to create a database named movabletype.
mysqladmin create movabletype -u username -p
Replace "username" with the user name you want use to access the database. Enter the password for the user name you created. If the database is created successfully, you see no information on the screen.
>>>
This looks to me like it's wrong. You don't replace "username" with the username used to access the Movable Type database. That will just give you an error since you're trying to sign in using a username that doesn't exist yet. You replace "username" with the MySQL administrator username. Then once signed in to MySQL as the MySQL administrator, you need extra steps to create a DIFFERENT username which is then used to access the Movable Type database.
(If you look at the instructions for creating the database using other routes, like phpMyAdmin, this is what they tell you to do.)
I think the instructions for creating the Movable Type database from the shell, should say something like the following:
***
$ mysql -u adminusername -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 5340 to server version: 3.23.54
Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
mysql> CREATE DATABASE movabletype;
Query OK, 1 row affected (0.00 sec)
mysql> GRANT ALL PRIVILEGES ON movabletype.* TO "movabletypeusername"@"localhost"
-> IDENTIFIED BY "password";
Query OK, 0 rows affected (0.00 sec)
mysql> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.01 sec)
mysql> EXIT
Bye
$
***
where, in the above commands:
- "adminusername" should be replaced with the MySQL administrator username. This would have been created back when you installed MySQL. Often it will just be called "root".
- "movabletypeusername" should be replaced with the username that you want to create to access the Movable Type database. This is not a pre-existing username; typing the above commands will create the new username. For good security, this should be *different* from the adminusername that is used to administer MySQL.
- "password" should be replaced with the password that you want to use with the newly-created "movabletypeusername" MySQL account. Again, it is good security practice to make this different from the password for the MySQL administrator account (and also, different from the password that you used to connect to the machine in the first place).
Write down the values that you used for "movabletypeusername" and "password" since you will need to re-enter them later on in the Movable Type installation process.
***
I have verified that these instructions worked for me when I used them during the Movable Type installation process. Hope this is helpful.

You're right Bennett!
Though in over 98% cases, the user would create the database from inside his/hers hosting account control panel using a very simple procedure, those that want to create the database from the shell need first to connect to MYSQL with the admin access and then eventually create a different user for the to be created movable type database.
Thanks for your contribution on this!