An expressive-type of instrument very much like a vocal. A lead may be anything from a riff, a hook, a vocal-made-lead line, or any instrument that takes centre stage in a mix. Being so similar to a vocal instrument in rhythm, pitch and performance, it can either be replaced by a vocal or it may work with one too.
One method of creating a lead line is to record a live performance via a MIDI track. This way it sounds less computerized when compared to that of simply drawing MIDI notes with the cursor tool.
Lock your track into a scale by placing a MIDI Scale effect to avoid any inharmonic dissonances.
Once again, think about a vocal performance that is sung compared to one that can be drawn on a computer screen. By simply drawing notes, the element of the performance is eliminated creating a relatively unexpressive lead line that is designed to be in the spotlight of a mix.
A good lead line can be described as relatable. Leads will primarily utilize the most sensitive band of frequencies to the human ear for this very reason, the relationship between the frequency itself and human perception. As a lead works within this range, it will be one of the few elements that sticks with the listener.
When writing leads, a combination of techniques used in previous stages may be compiled during lead creation. For example, you may “re-visit” the main harmony every now and again, just to bridge the connection and assist the general progression.
Another method of generating leads is by using existing parts/sections and manipulating those elements. MIDI functions such as :2, *2, legato, invert and reverse offer great alternatives for leads as you can now simply copy the harmony or melody and shrink notes so they play a “faster” melody. Upon hearing this technique, it can very well inspire more ideas based upon sonics.
Leads must flow, again much like a vocal. Rarely do vocalists hit perfectly quantized pitches. In other words, words flow into one another by bending to other pitches in a portamento type fashion (or “glide” in some cases).
When recording or creating a lead performance, avoid big jumps too far away from the preceding note. You want to “journey” your way there. For instance, instead of jumping from a C to a G, try including a stepping stone note in between to fill that gap in. You might try hitting the E before reaching the G.