In the last article we looked at how to plug yourself into the computer, this time we’re going to look at what to do with the sound once it arrives. The software is the key to your computer based studio, it gives you the tools to record, edit, process and mix your music. The evolution of music recording software is such that no one really knows what to call it anymore. Most programs began life as MIDI sequencers. Later on they bolted on support for the odd imported audio track, then actual audio recording, effects and mixing, video import, and finally software instruments. So, they are sort of MIDI sequencing, audio recording, mixing, effecting, editing, sound generating, arranging and mastering, compositional, music making and media production packages.

There are a few contenders out there all of which, by and large, have the same key features and I’ll mention them as we go. Rather than trying to compare feature sets side by side we’re going to look the main things they are all capable of.

MIDI Sequencing

Sequencing comes from the days of analogue synths where you would set up a cycle of control voltages to trigger different notes. These would be run as a sequence of maybe 8 or 16 notes and the synth pop of the early ‘80s was born. When MIDI and digital synths came along the idea of sequencing remained but the technology allowed for far more than a single sequence of notes.

MIDI – Musical Instrument Digital Interface. It’s a computer language that enables electronic devices to talk to each other. At a basic level it sends information like “play this note, this hard for this long” but it can also send all sorts of control information like pitch bend, modulation, sustain, filter frequency, fader position, tempo in fact pretty much anything that you are likely to find on a digital electronic instrument. The practical upshot is that you can have a single MIDI keyboard and play/control a whole load of MIDI sound modules, or in sequencing terms you can record all the notes played and parameters changed from any MIDI device connected to the computer. MIDI can use 16 independent channels per port and uses values between 0 and 127.

MIDI contained not just note information but velocity, pitch bend, modulation, aftertouch, patch change and all sorts of performance related data that could be recorded into a sequencer and then played back through any MIDI sound device. The advantage over recording the sound of a synth to tape was that it gave you the ability to edit the performance and change the sounds being used. You could also tweak the various parameters, quantise so your sloppy playing was brought into line with the tempo of the song, and change the tempo entirely without changing the pitch. Before computers, sequencers were hardware boxes and using them felt a lot like programming a machine. When computers arrived, that could display the MIDI information on screen and allow it to be edited, sequencing was revolutionised. In the early days there were two competing sequencing programs from Germany, “Notator Logic” from Emagic which used musical notation to display the information and Cubase from Steinberg which opted for what has become the standard MIDI editing interface – the Piano Roll.

The piano roll editor is largely unchanged today and takes its cue from the piano rolls put into automatic pianos that you see in cowboy film saloons. It’s basically a grid with the piano keyboard, and therefore pitch, going up the left side and time, and therefore note duration, going left to right. They also tend to show other controller information like velocity at the bottom beneath the notes. This sort of editor allowed people who didn’t read music to use the software and start making music, much to the annoyance of the established musical community.

MIDI sequencing and scoring are two sides of the same coin. The information shown on a score and a piano roll are essentially the same and most MIDI sequencers will allow you to see the MIDI as a score. However, producing a finished score does require a bit more in terms of aesthetic for publishing and there are specialised scoring software packages that are designed for that sole purpose. If publishing scores, or working purely with notation is what you prefer then Sibelius or Coda Finale would be where you need to look.

Audio Recording

In the mid 1990’s as the Apple Mac and Windows based IBM PC began to evolve the possibilities of sound recording started to emerge. By the time Windows 95 came along computer technology had advanced well beyond what was required to move digital audio through it’s circuits, and fifty quids worth of software seemed to be able to do everything that a professional Pro Tools system could do and for a fraction of the cost. Programs like Cubase and Twelve Tone’s Cakewalk surfed the front edge of the technology squeezing out amazing audio facilities that the professional world seemed to insist wasn’t possible without serious investment in specialised hardware.

Digidesign’s Pro Tools system remains the standard computer based recording system in professional studios but it has only recently caught up, feature wise, with the likes of Cubase and Cakewalk (now called Sonar).

Audio recording on a computer is a simple affair. Audio tracks are displayed alongside MIDI tracks and so the convention of a vertical list of tracks and a horizontal time base has remained. For each track can select an input from whatever inputs are available on your soundcard. Arm the track or tracks for recording, check the levels and click the “Record” button on the displayed transport bar. Computers are plenty fast enough to cope with the idea of monitoring audio and effects live through the software – this may seem an obvious requirement but not long ago delays in the region of half a second between the input and output of audio meant this was impossible. As you record the time line scrolls along and a visual representation of the wave file is displayed. Digital audio is completely non linear, to the computer it’s just data that can be accessed at any point at any time. The fun you used to have trying to get a tape machine to return to zero is now history, you can instantly playback from any point in time. You can mark two points and seamlessly loop a piece of audio for continuous playback, or jump from one part of a track instantly to somewhere else. In the first article in this series I mentioned the copying and pasting of audio – just like text in a word processor you can chop up and move around digital audio, copy it, paste it, loop it, even reverse it. A practical example would be to record a couple of bars of a new riff you’ve been working on, copy and paste it a hundred times and then play alongside working out the second guitar part. One recent innovation is that of multiple take recording. For instance you’re working on the vocal for the chorus, you can loop the project so that the chorus plays back over and over, hit record and your singer can keep on singing and every loop produces an individual recording. You can then go back and choose the best take or even better choose the best parts out of different takes and comp them together. With the exception of Pro Tools there’s no software imposed limit on audio tracks so you can keep trying various ways of doing things without fear of running out. I’ve managed to get over 250 tracks of CD quality audio playing back off a regular PC with a regular internal hard drive. If you want to record in 24bit 96kHz then you’ll get about a third as many tracks, so 70 would be a good number for a regular hard drive and over 100 for two drives in a RAID0 configuration.

Hard Drives

This is what we are recording to. They are a mechanical device with moving parts and specifications like spin speeds and access times which pretend to mean a lot to some people. A few years ago the type and speed of hard drive was really important. Professionals used SCSI (Small Computer Serial Interface) drives which had the superior speeds needed for audio work. In recent times SCSI has become more or less obsolete with regular hard drives being easily capable of the job. The standard internal hard drive will have a spin speed of 7200rpm, which is plenty and it’s actually the interface to the motherboard that can cause a bottleneck. The standard Parallel ATA connection has given way to the faster Serial ATA connection meaning that newer systems have even better/faster drives – hooray! One way of improving the audio performance of your system is to use RAID (Redundant Array of Inexpensive Disks). This was designed for servers really but the technology is useful in that using RAID”0” we can combine two or more hard drives that are “striped” into a single high performance drive. You can get about a 40% increase in track count, if you need it, the only proviso being that if one drive fails you loose all the data. Laptops generally come with smaller and slower 5400rpm hard drives. These are capable of about 40 tracks of 24bit 96kHz audio which is still rather good and you can get faster 2.5” laptop drives. There’s also the option of external hard drives that can connect via USB or Firewire that will give laptops better audio performance.

Mixing

The early digital recording software didn’t have much in the way of mixing facilities assuming you were going to run through an external mixer and mix in the old school fashion. Today there are few reasons to run any audio out of the computer except for monitoring. Your recording software will have virtual faders and knobs for every parameter and the magic of MIDI control means you can have an external control surface with whatever knobs and faders you desire. Each channel will have multiple inserts and sends for effects as well as parametric EQ and dynamics processing. The software will come with a range of useful effects such as modulation, delay, compression, reverb and filtering but they also support third party effects via various plug-in standards. Similar to filters in Photoshop you can buy additional effects that literally plug into your software and appear alongside the included ones. This allows companies such as Sony/Oxford, TC Electronic, Lexicon, Waves and Focusrite to produce software versions of their hardware effects units and gives you professional studio quality effects within your software. Two companies, TC Electronic and Universal Audio, have produced hardware units, called “DSP cards” to run their own software effects, taking the load from the computer. This is quite an important point. Computers are not limitless in their power, they can only think so hard for so long and so the actual number of audio tracks they can record and the actual number of effects (and software instruments) that can be run will depend on the power of the system. There’s a balancing act going on and each time you add an effect the computer is having to do more maths, and each time you add an audio track the computer has to move more data. At some point the computer will max out and the playback will glitch or crackle. Remove some effects and you’ll be able to do more tracks, mixdown some tracks and you’ll be able to use more effects. The limitations are there but most people don’t really find them and if you do there are many ways to work around them.

Arranging

Another legacy of the MIDI sequencer is the Arrange window, although it tends to be called things like the “Project” or “Session” window for no suitably explored reason. The Arrange window is an overview of your tracks of MIDI and audio where you can rearrange their positions in time. This is where all the cut copy and pasting goes one, cutting up tracks into blocks and moving them about. For instance you can slice the start and end of your middle 8 and put it somewhere else in the song.  Copy that piece of guitar from the intro and slap it into the ending. Duplicate a vocal track so that each one goes through different effects. One recent addition to the Arrange window is the ability to display the automation from the mixing and effects directly on the track. You can see, edit or create a volume envelope for an audio track, draw in a fade, or a panning sweep. Any inserted effects can be automated automated in the same way allowing you to draw in reverb depth changes so that they occur at exactly the right moment. This sort of power moves beyond recording and into post production.

Oh the wonder of it. How is your Portastudio looking these days?