Working on music and non music classification- when i tried to train i encountered the following error, can anyone help me in solving this issue,

[kletechuni]

student@student-Vostro-3669:~/sound-cnn$ python train.py 240 44100 /home/student/traindata 1000 150 Traceback (most recent call last): File "train.py", line 20, in classes,trainX,trainY,valX,valY,testX,testY = util.processAudio(bpm,samplingRate,mypath) File "/home/student/sound-cnn/utilities.py", line 29, in processAudio Ys = np.concatenate(labelList) ValueError: need at least one array to concatenate