Chapter 3: Generating Polyphonic Melodies

1. Vanishing gradients (values get multiplied by small values in each RNN step) and exploding gradients are common RNN problems that occur when training during the backpropagation step. LSTM provides a dedicated cell state that is modified by forget, input, and output gates to alleviate those problems.

2. Gated recurrent units (GRUs) are simpler but less expressive memory cells, where the forget and input gates are combined into a single update gate.

3. For a 3/4 time signature, you need 3 steps per quarter note, times 4 steps per quarter note, which equals 12 steps per bar. For a binary step counter to count to 12, you need 5 bits (like for 4/4 time) that will only count to 12. For 3 lookbacks, you'll need to look at the past 3 bars, with each bar being 12 steps, so you have [36, 24, 12].
4. The resulting vector is the sum of the previous...