mysqlservice command syntax
This sounds a lot like something I created back in February 2011. In fact, I placed the code for the mysqlservice script in one post : Running multiple instances on the same host (Sep 30, 2011)

The mysqlservice script is a quasi-service I created to help set up multiple mysql instances. The idea is to create


my.cnf for a specific port number
service filename to launch the service


In this case, you should see a file called /etc/init.d/mysql3307. If you do not have one, please create it. It should look like this :

#!/bin/sh
#
# readahead:    Prereads programs required for startup into memory
#
# chkconfig: 2345 4 99
# description:  This service causes the programs used during startup \
#               to be loaded into memory before they are needed,\
#               thus improving startup performance
#
#

# Sanity checks.
[ -x /usr/sbin/readahead ] || exit 0

# Check for &gt; 384 MB
#free -m | gawk '/Mem:/ {exit ($2 &gt;= 384)?0:1}' || exit 0

# Source function library.
#. /etc/rc.d/init.d/functions

WHICH=/usr/bin/which
SERVICE=`${WHICH} service`

MYSQL=`${WHICH} mysql`
PORT_NUMBER=3307

# See how we were called.
case "$1" in
    start)      ${SERVICE} mysqlservice ${PORT_NUMBER} start    ;;
    stop)       ${SERVICE} mysqlservice ${PORT_NUMBER} stop     ;;
    status)     ${SERVICE} mysqlservice ${PORT_NUMBER} status   ;;
    restart)    ${SERVICE} mysqlservice ${PORT_NUMBER} restart  ;;
    mycnf)      ${SERVICE} mysqlservice ${PORT_NUMBER} mycnf    ;;
    edit)       ${SERVICE} mysqlservice ${PORT_NUMBER} edit     ;;
    *)
        echo $"Usage: $0 {start|stop|restart|status|mycnf}"
        ;;
esac


After creating the file, please run 

chmod +x /etc/init.d/mysql3307


Now, the service can be summoned with

service mysql3307 start


Under the hood, it will call

service mysqlservice 3307 start


You could call it that way as well. Yet, setting up /etc/init.d/mysql3307 makes the service have a name that's easy to remember.

Give it a Try !!!

CAVEAT : You have to create a my.cnf file for port 3307 called /etc/my3307.cnf

The file /etc/my3307.cnf must include 

[mysqld]
port=3307
datadir=&lt;whatever folder you have for 3307's mysql instance&gt;


The fundamentals difference between services are


datadir
port number


You can start and stop the services independent of each other. While mysqld_multi allows you to have multiple MySQL Instances under one my.cnf via setting up mysqld groups, I created the mysqlservice quasi-service to use distinct my.cnf files for each instance. That way, you do not have to worry setting up my.cnf to know  what is common to all MySQL Instances vs. what is unique to each MySQL Instance.

If you setup more than two services in this manner, you become responsible for assigning the proper amount of RAM for buffers, caches, and threads.