# MusicPropertyContainer A protocol for music items that allow loading additional properties that you can fetch asynchronously. ``` protocol MusicPropertyContainer ``` ## Topics ### Instance Methods [`func with([PartialMusicAsyncProperty]) async throws -> Self`](/documentation/MusicKit/MusicPropertyContainer/with(_:)) Loads a new instance of the music item that includes the specified properties. [`func with([PartialMusicAsyncProperty], preferredSource: MusicPropertySource) async throws -> Self`](/documentation/MusicKit/MusicPropertyContainer/with(_:preferredSource:)-8ec7p) Loads a new instance of the music item that includes the specified properties. [`func with(PartialMusicAsyncProperty..., preferredSource: MusicPropertySource) async throws -> Self`](/documentation/MusicKit/MusicPropertyContainer/with(_:preferredSource:)-9wqhc) Loads a new instance of the music item that includes the specified properties. ## Relationships ### Conforming Types [`Song`](/documentation/MusicKit/Song) [`Artist`](/documentation/MusicKit/Artist) [`Album`](/documentation/MusicKit/Album) [`RadioShow`](/documentation/MusicKit/RadioShow) [`Genre`](/documentation/MusicKit/Genre) [`Station`](/documentation/MusicKit/Station) [`Playlist`](/documentation/MusicKit/Playlist) [`Track`](/documentation/MusicKit/Track) [`Item-swift.enum`](/documentation/MusicKit/Playlist/Entry/Item-swift.enum) [`Curator`](/documentation/MusicKit/Curator) [`MusicVideo`](/documentation/MusicKit/MusicVideo) [`RecordLabel`](/documentation/MusicKit/RecordLabel) [`Item-swift.enum`](/documentation/MusicKit/MusicPlayer/Queue/Entry/Item-swift.enum) [`Entry`](/documentation/MusicKit/Playlist/Entry) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)