You are downloading the Piano XAP file v1.0.0.0 for Windows Phone. Piano is a free Music App: Guys go for SARGAM MULTIPLE MUSIC BOX if you want multiple musical instruments in same app. Search for sargam in app store. Sargam contains 9 musical. You can now download the offline XAP package file to install & try it.
Download Locations for Piano 1.0.0.0 XAP file
Package File
Please Click Here > to retrieve available package files for Piano.
Please be aware that the Piano XAP file you are to download is hosted on the Microsoft Store CDN server. You can read more about Piano or get it on Microsoft Store.
To try to install it manually from an SD card, you should choose one of the server location above to get the offline Piano XAP file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.