How to set iTunes 11 in shuffle or repeat mode via applescript

For the new Music app, this works. If you're using iTunes still, change "Music" to "iTunes".

Repeat can be set to one or off or all.

tell application "Music"
   set song repeat to off
end

Shuffle can be set to true or false.

tell application "Music"
   set shuffle enabled to true
end

You can find more details at Dougscripts.

I was optimistic when I saw the AppleScript property current playlist of the iTunes application, but it doesn't work well. It's able to get and set the current playlist's name, but it can do neither for the properties shuffle or song repeat. It errors when trying to set either property, and it always returns 'false' for shuffle and 'off' for song repeat.

I think your only option is UI Scripting. Here's how to toggle shuffle through the menu bar:

tell application "System Events" to perform action "AXPress" of (first menu item of process "iTunes"'s menu bar 1's menu bar item "Controls"'s menu 1's menu item "Shuffle"'s menu 1 whose name ends with "Shuffle")

And here's how to set repeat:

tell application "System Events" to tell process "iTunes"'s menu bar 1's menu bar item "Controls"'s menu 1's menu item "Repeat"'s menu 1
    perform action "AXPress" of menu item "Off"
    perform action "AXPress" of menu item "All"
    perform action "AXPress" of menu item "One"
end tell

I liked John Sauer's approach so much I wrote myself some getters/setters for these properties using his approach. It's works well because you do not have to activate iTunes before using them. Anyway, I thought I'd post them in case they're of help to anyone. You will get or set their values using the "types" (modeled after the menu item names) as follows:

Repeat types are "Off", "All", or "One".

Shuffle types are "Off", "By Songs", "By Albums", or "By Groupings"

on getRepeatType() -- the return value is a string: Off/All/One
    tell application "System Events"
        tell process "iTunes"
            set menuItems to menu items of menu bar 1's menu bar item "Controls"'s menu 1's menu item "Repeat"'s menu 1
            set currentChoice to "unknown"
            repeat with anItem in menuItems
                try
                    set theResult to value of attribute "AXMenuItemMarkChar" of anItem
                    if theResult is not "" then
                        set currentChoice to name of anItem
                        exit repeat
                    end if
                end try
            end repeat
        end tell
    end tell
    return currentChoice
end getRepeatType

on setRepeatType(repeatType) -- repeatType is a string: Off/All/One
    set currentValue to my getRepeatType()
    ignoring case
        if currentValue is not repeatType then
            tell application "System Events" to tell process "iTunes"'s menu bar 1's menu bar item "Controls"'s menu 1's menu item "Repeat"'s menu 1
                if repeatType is "all" then
                    perform action "AXPress" of menu item "All"
                else if repeatType is "one" then
                    perform action "AXPress" of menu item "One"
                else
                    perform action "AXPress" of menu item "Off"
                end if
            end tell
        end if
    end ignoring
end setRepeatType

on getShuffleType() -- the return value is a string: Off/By Songs/By Albums/By Groupings
    tell application "System Events"
        tell process "iTunes"
            set menuItems to menu items of menu bar 1's menu bar item "Controls"'s menu 1's menu item "Shuffle"'s menu 1
            set onOffItemName to name of item 1 of menuItems
        end tell
    end tell

    -- is shuffle off
    ignoring case
        if onOffItemName contains " on " then return "Off"
    end ignoring

    -- shuffle is on so find how we are shuffling
    set currentChoice to "Unknown"
    tell application "System Events"
        tell process "iTunes"
            repeat with i from 2 to count of menuItems
                set anItem to item i of menuItems
                try
                    set theResult to value of attribute "AXMenuItemMarkChar" of anItem
                    if theResult is not "" then
                        set currentChoice to name of anItem
                        exit repeat
                    end if
                end try
            end repeat
        end tell
    end tell
    return currentChoice
end getShuffleType

on setShuffleType(shuffleType) -- shuffleType is a string:  Off/By Songs/By Albums/By Groupings
    set currentValue to my getShuffleType()

    script subs
        on toggleShuffleOnOff()
            tell application "System Events" to perform action "AXPress" of (first menu item of process "iTunes"'s menu bar 1's menu bar item "Controls"'s menu 1's menu item "Shuffle"'s menu 1 whose name ends with "Shuffle")
        end toggleShuffleOnOff

        on pressBySongs()
            tell application "System Events" to perform action "AXPress" of (first menu item of process "iTunes"'s menu bar 1's menu bar item "Controls"'s menu 1's menu item "Shuffle"'s menu 1 whose name ends with "Songs")
        end pressBySongs

        on pressByAlbums()
            tell application "System Events" to perform action "AXPress" of (first menu item of process "iTunes"'s menu bar 1's menu bar item "Controls"'s menu 1's menu item "Shuffle"'s menu 1 whose name ends with "Albums")
        end pressByAlbums

        on pressByGroupings()
            tell application "System Events" to perform action "AXPress" of (first menu item of process "iTunes"'s menu bar 1's menu bar item "Controls"'s menu 1's menu item "Shuffle"'s menu 1 whose name ends with "Groupings")
        end pressByGroupings
    end script

    ignoring case
        if shuffleType contains "off" then -- we have to make sure it's off
            if currentValue does not contain "off" then subs's toggleShuffleOnOff()
        else
            -- make sure it's on
            if currentValue contains "off" then subs's toggleShuffleOnOff()

            -- select the shuffle menu item for the type
            if shuffleType contains "song" and currentValue does not contain "song" then
                subs's pressBySongs()
            else if shuffleType contains "album" and currentValue does not contain "album" then
                subs's pressByAlbums()
            else if shuffleType contains "group" and currentValue does not contain "group" then
                subs's pressByGroupings()
            end if
        end if
    end ignoring
end setShuffleType