Remember the impressive rendering of the Ghostbusters theme tune in Activision's megagame? Now, that same company has produced a music composer program for the Commodore 64 that looks like being just as clever: it lets you use colour and even write your own lyrics. Producing a smash hit couldn't be easier....

There's probably been more than enough music composer/synthesizer packages developed for the Commodore 64, most of them had some pretty severe limitations. What a pleasant surprise to discover that Activision's beautifully written Music Composer package seems to have found its way round most of its predecessor's hang-ups.

Two versions of Music Studio are available: the cassette version on review here and a slightly more advanced version for disk users. It will cost you £14.99 on cassette and £19.99 on disk.

In both cases, the software arrives in a library-sized case along with a truly pocket-sized manual (comprehensive despite its size), and a supplement for users of the cassette version. In any case, the Music Studio manual provides all the necessary information to get you started quickly.

Loading from cassette takes just over three minutes and while you're waiting, you're entertained with a hi-res picture of a studio foyer. When loading ins completed, you are requested to 'press stop on tape', and select an input device. Music Studio lets you use either a joystick or a touchpad (such as the Koala-pad) to manipulate the 'baton'-shaped cursor.

The music editor screen is dominated by the stave (the ten lines that you write music on), with the lower third of the screen given over to the 'menu'. Each item on the menu is depicted by a picture or symbol. When the cursor rests over the picture of the function you wish to use, simply pressing the fire-button will set things in motion.

Perhaps the most graphic example (no pun intended) is the trash can. Positioning the cursor over the trash can picture and pressing the fire-button twice (to prevent accidents) will completely erase all the music, leaving you with a blank stave. Similarly, there are pictures of a printer (for printing your music), a cassette (for load and save options) etc.

Writing music couldn't be simpler. Move the cursor over to the note symbol, press the fire button to select note entry and again to alter the note length (from semiquaver to semibreve) if you desire, and move the cursor up to the stave. As you reach the bottom of the stave the cursor is replaced by the selected note and you simply position it at the desired place on the stave.

Pressing the fire button fixes the note in place and you can then position another note. As the note moves up and down the stave, Music Studio plays that note so you know where it ought to go.

Adjacent to the note symbol in the menu are symbols for rests, dotted notes, incidentals (sharps and flats), and even triplets (a triplet is three notes played in the same length of time that you would normally play four notes).

When you have entered a few notes, you'll be eager to hear what you have written. Simply point the cursor at the picture of an ear, press the button, and Music Studio obliges with a note-perfect rendition of the masterpiece you have just written.

A full range of editing commands are available; just select the appropriate symbol with the cursor and Music Studio responds. Various options include delete and insert a column (of notes), move a block of notes, copy a block of notes to another part of the stave etc. Selecting the picture of a synthesizer panel will get you through to the sound editor screen.

Editing sounds is every bit as easy as editing music, perhaps even easier! Along the bottom third of the sound editor screen is a menu of the default preset sounds that are automatically loaded with the main program. From this menu you can select such diverse sounds as Clarinet, Flute and Tuba from a choice of sixteen definable sounds.

To alter a sound to your own specification, simply select the function you wish to alter (wave shape, envelope, filter settings, etc) and modify to your heart's content.

Most of the sound functions are adjusted by selecting a fader with the cursor, pressing the button removes the cursor and allows up-down control using the joystick.

You have the choice of playing back a composition while you alter the sounds (select the ear symbol again) or selecting a continuous up-down scale of variable speed (very useful for adjusting the envelope controls).

If you wish, you can build up a whole collection of instruments and sound effects, name them, and save the whole lot to cassette (use the cassette symbol on this screen for saving sounds) for permanent storage.

The package's ease of use is not far removed from controlling an actual synthesizer panel, thanks to the pretty stunning graphics. To exit the screen, you simply take the cursor off the bottom of the page, press the fire-button and you arrive back at the music editor screen.

The manual describes this mode as a 'free-form method of composing' and it's designed for people who don't feel comfortable using real musical notation. So you use colours and shapes instead of choosing a real instrument and a series of notes: the idea is to 'paint' onto the stave rather than compose.

Although this, to me, seemed the least attractive part of Music Studio, it is intended to be a short-cut method of producing music. Moving back to the Music Editor screen converts your composition into standard musical notation. Like other compositions, these can also be saved to tape or disk.

Finally, an unusual facility in Music Studio is that it lets you write lyrics under the notes you've just composed. Once again, all you need do is choose the 'words' option on the menu, point the baton to the note to be written under, and type the word in from the keyboard. There's room for up to four verses.

Overall, this is a beautifully thought out and implemented piece of software. It's not only easy to use but pleasant to look at. The manual may be only pocket-sized but it's well documented - and it even gives you a brief tutorial on music theory. Apart from all that, it's very reasonably priced and must represent good value.