ACC File

What are ACC files and how to open them

Are you having problems opening an ACC file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your ACC files.

What is an ACC file?

ACC files have multiple uses, and Lotus Accessory is one of them. Read more about the other uses further down the page.

Lotus Accessory

These ACC files contain a spreadsheet created using Lotus Accessory, a reliable and easy-to-use spreadsheet software that contains a large variety of features. It became available in the days of the IBM PC, which had no graphical user interface. This tool allows you to create spreadsheets and graphical packages. You can use it to create and manage your databases.

How to open ACC files

Important: Different programs may use files with the ACC file extension for different purposes, so unless you are sure which format your ACC file is, you may need to try a few different programs.

While we have not verified the apps ourselves yet, our users have suggested ten different ACC openers which you will find listed below.

Last updated: August 16, 2026

All known file formats using extension .ACC

While Lotus Accessory is a popular type of ACC-file, we know of 2 different uses of the .ACC file extension. Different software may use files with the same extension for different types of data.

Philips Music Creator Data

Philips Music Creator Data files (extension .ACC) store accompaniment data used by the Philips Music Creator software that runs on the MSX computer together with the Philips NMS-1205 Music Module. ACC files hold pre-programmed background arrangements (styles) which Music Creator can load and use so that when composing or performing, rhythm, chord and bass patterns play in sync with user input. These files do not include melodies played by the user, but rather the supporting parts for accompaniment.

Music Creator creates ACC files through its Composer section when saving accompaniment data after selecting rhythm style, tempo, and the set of voices (instruments) for each accompaniment channel. A typical workflow: user chooses a style, configures which instruments play in the accompaniment channels (often six accompaniment voices plus a bass channel), sets tempo and effect settings, then saves those settings as an .ACC file. During playback, the ACC file is loaded by the software, which causes those accompaniment channels to run according to their saved patterns and instrument choices while allowing the user to add melody live using the connected keyboard.

ACC files are part of a suite of related formats in Music Creator, alongside .VOC for voice/instrument data, .SAM for sampled percussion, .SEQ for full song sequences, .RLT for real-time recordings, and .SPT for step-time song input.

Internally, ACC files generated for this format begin with the ASCII header string MUSICBOX at offset 0, which identifies them as Philips Music Creator accompaniment data files.

Various apps that use files with this extension

These apps are known to open certain types of ACC files. Remember, different programs may use ACC files for different purposes, so you may need to try out a few of them to be able to open your specific file.

Help us help others

File.org helps thousands of users every day, and we would love to hear from you if you have additional information about ACC file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.