Tollbar now displays all tools
Preroll click option
New Score Wizard
Over 30 Templates and unlimited user created template
Transposed or "C" score option.
Beginning measure number offset
Preset Tab tunings option
Added menu items
Auto Spacing when dragging notes, barlines and systems
Enhanced MIDI playback
Garritan Personal Studio ready
Simplified Accidentals option
More shortcuts
Music XML import and export
Full DLS and Soundfont support
Handwritten Music Style option
Bonus - Hundreds of works by J.S. Bach formatted in Encore, ready to use

Installation/Registration
Installation is now simply "drag and drop". 
After opening the .dmg file, drag Encore to your hard drive - most likely to your Applications folder.
Encore runs in "Demo" mode by default.  To enable the full features, launch Encore, then select "About Encore" from the "Encore" Menu.  A dialog box will appear where you must enter the serial number given to you when purchasing the product.  
To register Encore for all users on one computer, you must log in to an administrator's account before submitting the serial number.

Files Created in Older Versions
You can open files created in older versions of Encore, MusicTime Deluxe, or Master Tracks Pro. When opening an older file, it is advised to immediately choose "save as", creating a new file. Then close and reopen the new file before working with the document.

MIDI
- CoreMIDI implementation has been greatly improved in this version, with some significant changes to the MIDI settings.
- The Built-in Synth (using OSX's DLS Music Device AU) is now treated the same as any MIDI device. You can now mix all external and built-in devices, playing them all simultaneously.
- There is now support for Soundfont and DLS soundbanks. Place the SF2 or DLS soundbanks you want to use in the ~/Library/Audio/Sounds/Banks folder. In Encore, these files become an extension to the Built-in Synth. You can choose the SF2/DLS soundbank in the "Synthesizer" menu in the QT Instrument Selection Window. At this time, only one soundbank can be loaded at a time. If you have multiple scores open, any change to a soundbank file will affect all scores.
- The concepts of MIDI "Drivers" and "Ports" have been eliminated. You now select MIDI devices per-staff by clicking on the staff's "channel" cell in the Staff Sheet Window.  A check box gives you the option to change all staves to the same device at once. For scores saved in older versions, PortA will be translated as the Built-in Synth and PortB will default to the first found external MIDI device.
- Encore also now supports "Virtual Ports".  When enabled in the MIDI Setup Window, Encore presents an input and output port for other applications to send/receive ALL MIDI data.
- You now have the option to record from "All" MIDI devices, a specific device, or "None".  Be careful of MIDI feedback loops! It has been noticed that OSX's IAC Buses tend to feedback.  In general if you want to send MIDI to another application, let the Virtual Device handle it.  However, if you do use an IAC Bus as your output device, make sure you do not have the IAC Bus or "All" set as your input device, as feedback may occur and Encore will become noticeably sluggish.
- "MIDI Thru" now is only used as a genuine thru: input passed to output. You almost always will want to keep the setting on "Follow Current Staff".
- MIDI Sync is now disabled.

Preferences and Templates
Application preferences are now saved automatically every time you quit the application. If you want to set score-specific defaults for new documents, you must use a template file. Create a score with all the settings you want for the template, then choose "Save Settings to Template" from the "Setup" menu. The template file will be saved in the user's ~/Library/Application Support/GVOX/Templates folder.

Items that used to be saved in Preferences that are now only saved in the template file are:
- Marks (Play status and settings for accent, staccato and tenuto)
- Tempo Indication (Font) 
- Measure Endings (play status and font) 
- Coda phrases (play status and font) 
- Measure Numbers (Showing, layout and font) 
- Compressed Rests (Font)
- Text Elements (all)
- Show/Hide (all)
- Font selection for Staff Names 
- Spacing Defaults (all)

New Fonts
We have experimentally added a "handwritten" font to this version.  You can turn the font on from the application's "Setup" menu.  Note that currently that this is an application-wide option, you cannot save the font setting per-document.  Two text fonts that match the graphics are also included, called "NorText" and "NorTextExtra".

Keyboard Shortcuts
Spacebar now starts/stops playback in edit mode, as well as select mode.
'A' and 'P' keys each now act as a toggle between edit and select modes.
Cmd-; is now the shortcut for "Show/Hide"
Shift-cmd-B is now the shortcut for "Beam Group"
Shortcuts for "Save As", "Page Setup", and "Align Playback" have been added.
Added quick-keys for New Chord dialog, reflecting Windows version:
[ only works when 'custom' button is off -- a-g = roots, A-G = bass, 3-4 = root #/b, #-$ = bass #/b ]

Other changes to 4.5.6
Live scrolling and resizing for Score and Staff Windows.
Added standard "Window" Menu Functionality.
Created new windows for some dialog boxes, some of which now allow you to see results "live" while changing settings and before closing the window.
Added playing of note with shift-select.
Printing is now allowed in Demo mode, with "DEMO" text overlaid.
Changed  MIDI Thru to default to "follow staff"
Click can now be sent on any MIDI Device in the popup menu.
Set default channel for new percussion staves to 10.
Made drum map default to GM for new percussion staff.
Now can open files without write permission as an untitled, unsaved file.

Bug fixes to 4.5.6.4
Fixed problems launching application on 10.3
Fixed problems with MIDI messages sent when stopping.
Fixed crash when failing to open a locked file.

Correction de bugs

GVOX CEO Richard Hotchkiss calls the new upgrade "a substantial bug fix and optimization" for Encore users on the Apple platform. Encore 4.5.6 boasts improved performance, ranging from changes to onscreen look and feel to a vast improvement in overall speed.

Major advances focus on MIDI functions. Most notably, Encore's Real Time Transcription now performs smoothly and efficiently for Mac users.

Other improvements include:

Treating Apple's built-in synthesizer as a Device, allowing external and built-in devices to be used simultaneously.
The addition of Virtual Ports. When selected in the MIDI Setup Window, Encore presents an input and output port for other applications to send and receive MIDI data.