FLStudio. There are many ways to add audio tracks or wav files to your songs, you can drag .wav, .mp3, .FLAC & .ogg files from the FLStudio Browser or a Windows file browser and :
Drop the audio ...
I had my playback on in pattern mode and creating new instrument track by dropping sample into playlist changed playback mode from pattern to song. It works even if playback is turned off and it works for both audio and ...