FL HeartMuLa Tags Builder

FL HeartMuLa Tags Builder is the pack's quality-of-life node: a set of dropdowns that assemble the comma-separated style tags HeartMuLa uses to steer a song. It doesn't load a model, doesn't touch tensors, and takes milliseconds - it's pure string assembly. If the Conditioning node is where you write the song, this is the palette you pick the colors from.

What it does

You pick a genre, a vocal type, and a mood, and the node joins them - plus optional tempo, a second genre, instruments, and free-form extra tags - into one comma-separated string. That string is its single output (tags), and you wire it straight into FL HeartMuLa Conditioning's tags input.

The dropdowns cover the ground HeartMuLa actually understands: 24 genres (pop through cinematic), 8 vocal types (female vocal, male vocal, duet, choir, instrumental, vocal harmony, rap, spoken word), 16 moods, and 5 tempo levels. secondary_genre defaults to none and lets you do fusion tags like pop + jazz. instruments and additional_tags are free text for the stuff the dropdowns miss.

The honest take

You can type tags directly into the Conditioning node and get the same result - Tags Builder is a convenience, not a capability. But it earns its place for two reasons. First, consistency: typos like melancholic spelled wrong just become noise the model half-ignores, and dropdowns remove that failure mode entirely. Second, it's a nice legend - when you forget whether the pack expects hip-hop or hip hop, the dropdown answers for you.

One genuine quirk: because tag adherence is HeartMuLa's weak spot (the community consensus is that it follows lyrics far better than styles), don't expect a metal + aggressive combo to reliably deliver. The builder gives you the right vocabulary; the model's willingness to use it is a separate matter, and it mostly wants to write pop.

Installation

Part of the FL HeartMuLa pack, so:

cd ComfyUI/custom_nodes
git clone https://github.com/filliptm/ComfyUI_FL-HeartMuLa.git
cd ComfyUI_FL-HeartMuLa
pip install -r requirements.txt

Or ComfyUI Manager → search "FL HeartMuLa" → Install → restart. No model download needed for this node - it works standalone, though it's only useful when wired into a Conditioning node that is.

Troubleshooting

• Tags don't seem to do anything - that's the model, not the builder. Raise cfg_scale toward 3 on the Conditioning node and reroll; some tags just won't land.
• Tags arrive lowercase / reformatted - expected; the pack lowercases and cleans tags internally before conditioning.
• Wire shows a string, not a connection - the output is a plain STRING, which ComfyUI may let you drop in as a widget value too. Either way works.

If you're iterating on one song and keep changing two words, the builder is overkill. If you're running batches of variations and want consistent, valid tag strings every time, it's exactly the small tool you want in the graph.