Update: Updated once more today, ArkTool with Source Code and GUI v6.1 for PS3 is available which now includes additional fixes and Linux support.

Recently xorloser released ArkTool with Source Code and GUI v5.2 for PS3 which can edit ARK/HDR files found in games including Guitar Hero 1, Guitar Hero 2, Guitar Hero 80s, Rockband, and Karaoke Revolution.

Today, he has updated it to ArkTool with Source Code and GUI v6.0 for PS3!

To quote from his page- v6.0 changes:

* now decrypts rockband song files on the fly when extracting them from ARK files

I've said it before, but these tools and source code will work with the following games for any system including PS2, PS3, X-Box, X-Box 360.
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Today xorloser let us know he has updated his tool (with PS3 support!) which can edit ARK/HDR files found in games including Guitar Hero 1, Guitar Hero 2, Guitar Hero 80s, Rockband, and Karaoke Revolution... Guitar Hero 3 uses a different format, so it is currently not supported.

Both the tool and source code will work with those titles for any system including PS3, PS2, X-Box 360, and X-Box. Note: In order to use this via PS3, you must have a Debug PS3 for the time being as there is no public way to run PS3 back-ups via retail consoles.

Download: ArkTool with Source Code and GUI v5.2 for PS3

You can now replace a short song with a longer song (ie replace a small file with a bigger file). Previously, no tools existed which allowed this kind of editing, and you could only make custom songs by replacing the existing songs with new songs that are the same size or smaller.
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