Sonar X2 replaces Track Layers with Take Lanes, which come with far more flexibility...
Take Lanes are 'sub-tracks' of a parent track. Compared to track folders, which are collections of independent tracks that can be different types (MIDI, audio, or instrument, for example), Take Lanes are subject to the parent track's effects, level, sends, pan, gain, volume, track automation, ProChannel processing, and type (MIDI or audio). Each Take Lane has independent Name, Mute, Solo, Record-enable and Edit filter settings. However, Record is linked to the parent track, so the parent track Record button disables Take Lane Record buttons. Enabling a Take Lane's Solo button mutes all other Take Lanes, although if Solo is not enabled, you can mute and unmute Take Lanes individually.
The Take Lanes button in the lower left of a parent track collapses or expands the Take Lanes. When collapsed, all Take Lanes are combined visually in the parent track into a single clip; for overlapping Takes, the uppermost Take Lane's clip is overlaid on top. However, all of the parent track's Take Lane clips, whether visible or not, will play back.
Remember that Take Lanes are indeed supposed to be Takes and not tracks, so the object is almost always to whittle them down to the best Takes for a particular part. If you have tracks carrying around eight or 10 Takes, start editing! Otherwise, use conventional tracks and track folders.
Take Lanes behave like track clips when editing; they can have their own clip automation, fades and inserted effects, be processed as V-Vocal clips, and so on. After making tweaks and changes to the clips, you can then bounce them together into a single, composite track.
Although Take Lanes are added automatically during loop recording, you can also add them manually by clicking the '+' button in a Take Lane's lower-left corner. Similarly, clicking the 'x' button in the lower left removes a Take Lane.
Take Lanes all 'auto-zoom' to the same height if you drag the splitter bar between Lanes up or down. As I'm usually comparing phrases in clips, this consistency is helpful. Also note that you can change the order of Take Lanes with drag-and-drop. I move the best Takes (where I end up doing the most tweaking) to the top of the stack, with the others further down.
The simplest way to use Take Lanes is for organising various Takes when trying out parts, or coming up with ideas. For example, with guitar, if there's an amp sim in the parent track you can try out different Takes more conveniently than cloning a track, each with its own instance of the amp sim, and collecting them in a track folder. However, the most common application is probably loop recording, where you can record multiple Takes of a part without stopping, then combine the best bits from the Takes to craft the perfect composite part.
To set up audio loop recording:
With MIDI-based loop recording, 'Sound on Sound' mode allows drum machine-style operation, where you can build tracks while listening to previous tracks. Overwrite still records all your Takes, but you won't hear previous Takes when you record a new one. This is ideal for trying out something like different piano parts, so you won't be distracted by previously played ones.
After finishing loop recording, you'll have multiple Take Lanes with clips. There are several ways to choose and combine the best parts. The optimum method depends on whether you're working with specific, easily defined sections (perhaps separate phrases with spaces in between), or doing more complex edits, such as cutting in the middle of phrases or splicing sustained notes.
Isolate phrases: This is an extremely quick way to work. Select the Mute tool from the Tools toolbar (or type Ctrl-F10), but instead of using it to Mute, hold down the Ctrl key and drag across a region containing the phrase you want to audition. Doing this mutes all equivalent regions in the other Take Lanes, so you'll hear only the phrase you've isolated. Do this for the same phrase in each Take Lane to audition each one, and when you find one you like, leave that one isolated. Then continue the same isolating process on subsequent phrases until you've isolated all the best bits.
You may still want to do some touch-ups, like muting the spaces between phrases, to minimise noise, or you may want to unmute an inhale that you muted previously. To make these kinds of changes, release the Ctrl key; now the Isolate tool reverts to the conventional Mute tool. Drag across the clip's top half to unmute a muted section, or across the clip's lower half to mute an unmuted section.
Now solo the track, and play it back to make sure all the edits work well together (for example, make sure that there aren't any abrupt transitions between phrases). Once you have the perfect Take, select all the clips, then select Bounce to Clip(s) from the Track View Clips menu to create a unified track.
Split and mute: This method creates physical splits between different phrases, so you can then mute or unmute entire sections without having to deal with 'dragging dexterity'. The easiest way to split is to select all Take Lanes, then place the Split tool (selected from the Edit Tool menu, by typing F8, or by holding down the Alt key while using the Smart Tool) where you want the split, and click. Alternatively, place the Now Time over where you want to split the selected clips, and type 'S'. Create these moving from right to left, as clips to the left of the split point are selected upon splitting. That way you don't have to keep re-selecting the clips to split them.
Now use the mute tool to click on clips you want to mute (click again to unmute). One advantage of this method is that you can delete all the muted clips, and create automatic fade-ins and fade-outs for the clips, to ensure smooth transitions. Select the clips for which you want to add fades, then, from the Track View Clips menu, choose Fade Clips (yes, the same option you've been using all these years to add tight fades before Acidising a clip!). Click Fade, then specify fade-in and fade-out times (5ms in, 7ms out is a good default choice) and fade curves. The Alter Existing Times and Curves buttons matter only if you're applying a fade to a clip that already has a fade.
Separate options in the same menu — Xfade and Max Gap — can help fill in spaces between clips. For example, suppose there's a 100ms gap between two clips, and you've specified a 20ms Xfade with 50ms for Max Gap. Nothing will happen if you invoke this, because the gap is bigger than 50ms. But specify 120ms or more, and the later clip's left edge will roll out 120ms to the left, thus covering the gap and creating a 20ms crossfade with the right edge of the first clip. This will apply to all selected clips where the gap between them meets the Xfade and Gap timing requirements.
Split and don't mute: You can also use Sonar's Audition function for playing back individual clips. Using the 'split and mute' technique, but without muting anything, select a clip, then click Play while holding the Shift key; you'll hear only the selected clip. Move down the clips in the stack until you find one you like, then delete the others. The advantage of this approach is that it's easy to hear how clips in different Lanes sound when combined. Click Take Lane 3 for the first phrase, then Ctrl-click Take Lane 1 for the second phrase, or whatever arbitrary order you want. Only the selected tracks will play back.
Detailed editing: Of course, you can go nuts with editing the Lane clips: add custom fades, nudge timings, change or normalise clip levels, add effects, use clip automation, or do anything else you would do with conventional track clip editing. When you really want to massage a vocal to perfection, it doesn't get much better than this.