Restructured the project structure back to the way it was, there's no reasonable way to split the modules

src/NadekoBot/Modules/Music/Services/IMusicService.cs

@@ -0,0 +1,36 @@
+using Nadeko.Bot.Db.Models;
+using System.Diagnostics.CodeAnalysis;
+
+namespace NadekoBot.Modules.Music.Services;
+
+public interface IMusicService : IPlaceholderProvider
+{
+    /// <summary>
+    ///     Leave voice channel in the specified guild if it's connected to one
+    /// </summary>
+    /// <param name="guildId">Id of the guild</param>
+    public Task LeaveVoiceChannelAsync(ulong guildId);
+
+    /// <summary>
+    ///     Joins the voice channel with the specified id
+    /// </summary>
+    /// <param name="guildId">Id of the guild where the voice channel is</param>
+    /// <param name="voiceChannelId">Id of the voice channel</param>
+    public Task JoinVoiceChannelAsync(ulong guildId, ulong voiceChannelId);
+
+    Task<IMusicPlayer?> GetOrCreateMusicPlayerAsync(ITextChannel contextChannel);
+    bool TryGetMusicPlayer(ulong guildId, [MaybeNullWhen(false)] out IMusicPlayer musicPlayer);
+    Task<int> EnqueueYoutubePlaylistAsync(IMusicPlayer mp, string playlistId, string queuer);
+    Task EnqueueDirectoryAsync(IMusicPlayer mp, string dirPath, string queuer);
+    Task<IUserMessage?> SendToOutputAsync(ulong guildId, IEmbedBuilder embed);
+    Task<bool> PlayAsync(ulong guildId, ulong voiceChannelId);
+    Task<IList<(string Title, string Url)>> SearchVideosAsync(string query);
+    Task<bool> SetMusicChannelAsync(ulong guildId, ulong? channelId);
+    Task SetRepeatAsync(ulong guildId, PlayerRepeatType repeatType);
+    Task SetVolumeAsync(ulong guildId, int value);
+    Task<bool> ToggleAutoDisconnectAsync(ulong guildId);
+    Task<QualityPreset> GetMusicQualityAsync(ulong guildId);
+    Task SetMusicQualityAsync(ulong guildId, QualityPreset preset);
+    Task<bool> ToggleQueueAutoPlayAsync(ulong guildId);
+    Task<bool> FairplayAsync(ulong guildId);
+}