Sequencing Software
Here are a few popular Sequencing Software programs:
Master Traks www.gvox.com
Cubase www.steigberg.com
Protools www.digidesign.com
Performer www.motu.com
Vision www.opcode.com
Cakewalk www.cakewalk.com

How to use Sequencers in your Music Classroom
There are three great examples which every music teacher can use MIDI Sequencers in their classroom: Accompanying, CAI (Computer Assisted Instruction) and Composition.
Sequencers & Accompanying
Every elementary teacher has music programs or pageants to present. You can record the program on a MIDI Sequencer. Then you can play it back for rehearsals and the performance. You could also make a tape recording for your students to practice at home.
If you are using a piano accompaniment, you can add other sounds when you record it for a program. You can also add other instruments like percussion or sound effects to spice up the accompaniment.
If you are using a composition that is well known, it will be on the internet as a MIDI file. You can download the MIDI file of this song and use it for your concert.
If you have some piano skills you can record it yourself instead of paying someone else to play for you.

What is a MIDI Sequencer?
A MIDI Sequencer records MIDI data. This MIDI data tells other equipment to turn on and off musical performance instructions. When you play a note on a MIDI keyboard, you are instructing the MIDI keyboard to play a note for a period of time and also how soft or loud that note will sound. The MIDI Sequencer will record and play back this data. The great thing about it is that most MIDI Sequencers will record more than one track.

A good analogy is a 4 Track Tape Recorder. Unlike a Multi-track recorder a MIDI Sequencer has an unlimited number of tracks that can be recorded on. Some MIDI Sequencers have as few as 2 tracks, most have at least 16 tracks. Some can have 1000+ tracks depending on the amount of memory your computer has. I do not think that anyone would need more than 32 tracks to record 99% of most projects.

How a MIDI Sequencer Works
A MIDI Sequencer records performance data not sound. This is why MIDI files are small. Think of a MIDI file as a player piano roll. The roll without the player piano is of little use. The player piano without the piano roll is also of little use. Both of them together can make beautiful music together.

When you play middle C on the keyboard the "piano roll" reads :Note on C3. When you stop playing middle C note the "piano roll" reads : Note off C3. All of this data is converted to 1's and 0's faster than a blink of an eye.

A Bad Piano Player, That's OK!
If you should have spent more time studying in class piano you can still make music on a MIDI Sequencer. You can play as fast or as slow as you want on a MIDI Sequencer. That is right, if you can not play something at 120 bpm you could play it in at 60 bpm then you can change the tempo back to actual tempo.

You can also play one hand at a time. Then you can combine the tracks together. You could also play both parts with either your right or left hand, whichever one you are strongest with on the piano.

If you still do not want to play piano there are other MIDI controllers like : Guitar, Wind and Percussion MIDI controllers.

Sequencers vs. CDs
There are many advantages that a MIDI Sequencer has over a standard CD player. A MIDI Sequencer can cut out parts from a sequence, it can change tempo, it can transpose parts, it can change instruments, it can add or take out sections of music and it can record your own music for a program or concert. You can not do any of these on a standard CD player.

Sequencers & CAI (Computer Assisted Instruction)
You can teach form using a MIDI Sequencer. If you wanted to teach rondo form you could have one student play an A section then have another student record a B section then you could copy and paste the A section after the B section.

The MIDI Sequencer can help you teach aural skills. You can record scales, intervals and chords in the MIDI Sequencer. You could copy and paste any of these a have a virtual aural skills teacher play them back for your class or with headphones for an advance student.

Sequencers & Composition
When I taught elementary music I had a unit on composition. One of the best ways to teach composition is to improvise. I used a MIDI keyboard connected to my computer sequencer. I would teach my students how to use the "black notes" of a piano to play a pentatonic scale. I was amazed how well my students "composed" music. We all would listen to one another's composition and make constructive comments on them. Then we would talk about the elements that made a composition sound better. This was a great section for my students.
I would also do a similar section on drum and percussion composition. The students would love when we did this unit.

MIDI Files and GM (General MIDI)
The Internet has thousand's and thousand's of MIDI files for you to download. Many of these files are "Classical' and "Folk Tunes" which you can use for your programs. Most of these MIDI files are GM MIDI files. GM (General MIDI) means that the sounds are standardized so that you do not have to program each sound yourself.

A Final Thought
I hope that this guide will help inspire you to use music technology in your classroom.